Why do we use Oxytocin?
Oxytocin
It has been shown that oxytocin differentially affects males and females. Females who are administered oxytocin are overall faster in responding to socially relevant stimuli than males who received oxytocin. Additionally, after the administration of oxytocin, females show increased amygdala activity in response to threatening scenes; however, males do not show increased amygdala activation. This phenomenon can be explained by looking at the role of gonadal hormones, specifically estrogen, which modulate the enhanced threat processing seen in females. Estrogen has been shown to stimulate the release of oxytocin from the hypothalamus and promote receptor binding in the amygdala.
Nociceptin
The N/OFQ-NOP system is found in central and peripheral nervous tissue, where it is well placed to modulate nociception, or the body's sensation of pain. Unlike morphine and other opioids that are used to alleviate pain, nociceptin's role in nociception is not straightforward. Administration of N/OFQ in the brain causes increased sensations of pain (hyperalgesia). This makes it unique from classic opioid peptides, which typically act as analgesics (pain relievers), as it means that nociceptin can even counteract analgesia, thus acting as an antiopioid. Additionally, blocking the nociceptin receptor can lead to an increased pain threshold and a decreased tolerance development to analgesic opioids. As such, nociceptin has a lower risk of addiction than many pain relievers that are currently used. Recent studies have proposed that this anti-analgesic function of nociceptin stems from the inhibition of the periaqueductal grey, which controls pain modulation from the central nervous system. This effect of nociceptin may lead to its future use as a method to reduce morphine dosage and decrease the development of tolerance and dependence. When administered to the spinal cord, nociceptin produces similar analgesic effects to classical opioids.
Oxytocin/ergometrine
Oxytocin/ergometrine (trade name Syntometrine) is an obstetric combination drug. The components are synthetically produced oxytocin, a human hormone produced in the hypothalamus, and ergometrine, an alpha-adrenergic, dopaminergic and serotonin (5-HT) receptor agonist.
Tend and befriend
Human and animal studies (reviewed in Taylor et al., 2000) suggest that oxytocin is the neuroendocrine mechanism underlying the female "befriend" stress response. Oxytocin administration to rats and prairie voles increased social contact and social grooming behaviors, reduced stress, and lowered aggression. In humans, oxytocin promotes mother-infant attachments, romantic pair bonds, and friendships. Social contact or support during stressful times leads to lowered sympathetic and neuroendocrine stress responses. Although social support downregulates these physiological stress responses in both men and women, women are more likely to seek social contact during stress. Furthermore, support from another female provides enhanced stress-reducing benefits to women. However, a review of female aggression noted that "The fact that OT [oxytocin] enhances, rather than diminishes, attention to potential threat in the environment casts doubt on the popular ‘tend-and-befriend’ hypothesis which is based on the presumed anxiolytic effect of OT".
Oxytocin (medication)
Oxytocin is marketed as a pheromone. Oxytocin in spray form is sold under the brands Attrakt and Connekt. It is not absorbed into the skin when used topically, but it may be inhaled in a manner similar to perfume applied to skin. Oxytocin sprays for insufflation are also sold, but often with little or no oxytocin at all.
Human bonding
Oxytocin is associated with higher levels of trust in laboratory studies on humans. It has been called the "cuddle chemical" for its role in facilitating trust and attachment. In the reward centers of the limbic system, the neurotransmitter dopamine may interact with oxytocin and further increase the likelihood of bonding. One team of researchers has argued that oxytocin only plays a secondary role in affiliation, and that endogenous opiates play the central role. According to this model, affiliation is a function of the brain systems underlying reward and memory formation.
Supraoptic nucleus
Vasopressin neurons and oxytocin neurons make many other neuroactive substances in addition to vasopressin and oxytocin, though most are present only in small quantities. However, some of these other substances are known to be important. Dynorphin produced by vasopressin neurons is involved in regulating the phasic discharge patterning of vasopressin neurons, and nitric oxide produced by both neuronal types is a negative-feedback regulator of cell activity. Oxytocin neurons also make dynorphin; in these neurons, dynorphin acts at the nerve terminals in the posterior pituitary as a negative feedback inhibitor of oxytocin secretion. Oxytocin neurons also make large amounts of cholecystokinin as well as the cocaine and amphetamine regulatory transcript (CART).
Oxytocin treatment for postpartum depression
Intranasal (IN) administration, as opposed to more conventional routes, such as oral or intravenous infusion, offers an alternative method for drug delivery. This method is often the preferred method. Oxytocin (OT) is a neuropeptide that can be administered in this manner. IN delivery methods are gaining popularity due to the non-invasive nature of the method. IN generally does not require complicated sterile preparations, is relatively painless, and often can be administered quickly by a medical doctor, or in some cases the patient. IN maximizes the convenience and comfort of the patient, making a treatment regimen more likely to be followed. During Postpartum Depression (PPD), some women may be less likely to seek treatment if treatment is inconvenient. In addition, new mothers (especially if suffering with depression) may feel socially isolated or overwhelmed by responsibilities of caring for a new infant. IN not only provides a convenient delivery method, but is also a logical choice based on efficacy. Tissue in nasal cavities is highly vascular, providing a large surface area for absorption. Large surface areas allow for quick drug onset, meaning greater potential for the drug to reach the central nervous system without undergoing first-pass metabolism. Avoiding first-pass metabolism allows more of the drug to be available for treatment. Gastrointestinal discomfort and digestive side-effects can also be avoided by IN dosage. IN delivery allows OT to cross the blood brain barrier, expediting the drug to the central nervous system and cerebrospinal fluid. The blood-brain-barrier normally protects the brain by blocking certain chemicals and toxins from reaching the brain. Increased levels of OT can be found in salivary samples after intranasal administration of the neuropeptide. Salivary OT levels can remain higher than baseline levels four hours after dosage, suggesting that OT is still producing an active response. This may be an effective way of monitoring levels of OT levels during short-term treatment or help identify women at risk of or have a history of PPD. Though OT can be administrered intravenously (and is sometimes the appropriate method depending on the medical situation), IN administration offers many advantages that make it an ideal choice for short-term treatment.
Toxic leukoencephalopathy
Oxycodone is the main active ingredient in various oral pain relief medications. High doses of opiates such as oxycodone can lead to leukoencephalopathy. The activity of various opioid and nociceptive receptors appear to play a role in the disease; however, the exact mechanism remains unknown.
Carbetocin
Carbetocin works as an oxytocic, antihemorrhagic and uterotonic drug in the peripheral nervous system. The most common causes of postpartum hemorrhage are lack of tone in the uterus from overstretching or the use of an anesthetic. Carbetocin has been approved for use immediately following an elective Cesarean section when a local or spinal anesthesia has been administered. Since the uterus cannot contract on its own following incision during a Cesarean section, exogenous administration of oxytocin or an analog is necessary to restore uterine tone and prevent hemorrhage.
Oxytocin
In the pituitary gland, oxytocin is packaged in large, dense-core vesicles, where it is bound to neurophysin I as shown in the inset of the figure; neurophysin is a large peptide fragment of the larger precursor protein molecule from which oxytocin is derived by enzymatic cleavage.
Social connection
In mammals, oxytocin has been found to be released during childbirth, breastfeeding, sexual stimulation, bonding, and in some cases stress. In 1992, Sue Carter discovered that administering oxytocin to prairie voles would accelerate their monogamous pair-bonding behavior. Oxytocin has also been found to play many roles in the bonding between mother and child. In addition to pair-bonding and motherhood, oxytocin has been found to play a role in prosocial behavior and bonding in humans. Nicknamed the “love drug” or “cuddle chemical,” plasma levels of oxytocin increase following physical affection, and are linked to more trusting and generous social behavior, positively biased social memory, attraction, and anxiety and hormonal responses. Further supporting a nuanced role in adult human bonding, greater circulating oxytocin over a 24-hour period was associated with greater love and perceptions of partner responsiveness and gratitude, however was also linked to perceptions of a relationship being vulnerable and in danger. Thus oxytocin may play a flexible role in relationship maintenance, supporting both the feelings that bring us closer and the distress and instinct to fight for an intimate bond in peril.
Antioxidant
Uric acid is by far the highest concentration antioxidant in human blood. Uric acid (UA) is an antioxidant oxypurine produced from xanthine by the enzyme xanthine oxidase, and is an intermediate product of purine metabolism. In almost all land animals, urate oxidase further catalyzes the oxidation of uric acid to allantoin, but in humans and most higher primates, the urate oxidase gene is nonfunctional, so that UA is not further broken down. The evolutionary reasons for this loss of urate conversion to allantoin remain the topic of active speculation. The antioxidant effects of uric acid have led researchers to suggest this mutation was beneficial to early primates and humans. Studies of high altitude acclimatization support the hypothesis that urate acts as an antioxidant by mitigating the oxidative stress caused by high-altitude hypoxia.
Fish physiology
Oxytocin is a group of neuropeptides found in most vertebrate. One form of oxytocin functions as a hormone which is associated with 
human love. In 2012, researchers injected cichlids from the social species "Neolamprologus pulcher", either with this form of isotocin or with a control saline solution. They found isotocin increased "responsiveness to social information", which suggests "it is a key regulator of social behavior that has evolved and endured since ancient times".
Carbetocin
Carbetocin (INN, BAN) (brand names Duratocin, Pabal, Lonactene, Depotocin, Comoton, Decomoton), or 1-butanoic acid-2-(O-methy--tyrosine)-1-carbaoxytocin, is an oxytocic used in obstetrics to control postpartum hemorrhage and bleeding after giving birth, particularly following Cesarean section. It is an eight amino acid long analogue of oxytocin (a nonapeptide) and has a similar mechanism of action. Carbetocin is an agonist at peripherally expressed oxytocin receptors. It is manufactured by Ferring Pharmaceuticals and is available in Canada and the United Kingdom and many other countries throughout the world, but not in the United States.
Oxymoron (album)
In February 2014, during a Q&A session for the album, at SONOS Studios in Los Angeles, California, Schoolboy Q described the song "Prescription/Oxymoron", as the most personal: "I came up selling OxyContin," he said. "The karma behind it was that I never took an OxyContin before but I did get addicted to Percocets, Xanax, Codeine—shit like that. When my daughter was one and two [years old], I used to get into sleep comas, like 'Xan comas'—just dead to the world and I put it into the music." Schoolboy Q said he arranged the song to juxtapose the process of selling prescription pills and addiction: "I put the OxyContin and selling it at the end of the relapse or the addiction," he said. "I sold OxyContin and then I got addicted [to pills]. This way, I showed that I got addicted then I sold it. That was a crazy record. That's true shit—the first part of it when my daughter tried to wake me up and I was dead to the world. That was my little secret. I always had the cup with me. They just never knew I had a gang of pills in the other bottle. That was a little story about me and how I was addicted, too."
Homewrecker
Scientific American, tongue-in-cheek, referred to oxytocin as a homewrecker. The hormone normally triggers a nesting instinct, which makes it a "home builder", not a homewrecker. But with chronic exposure in prairie voles, a study instead showed a breakdown of the normal nesting instincts: The animals avoided pair bonding and child nurturing. This raises questions about the growing practice of using oxytocin to treat behavior disorders such as autism.
Couples therapy
There has been interest in use of the so-called "love hormone" – oxytocin – during therapy sessions, although this is still largely experimental and somewhat controversial. Some researchers have argued oxytocin has a general enhancing effect on all social emotions, since intranasal administration of oxytocin also increases envy and "Schadenfreude". Also, oxytocin has also the potential for being abused in confidence tricks.
Oxytocin
While the structure of oxytocin is highly conserved in placental mammals, a novel structure of oxytocin was recently reported in marmosets, tamarins, and other new world primates. Genomic sequencing of the gene for oxytocin revealed a single in-frame mutation (thymine for cytosine) which results in a single amino acid substitution at the 8-position (proline for leucine). Since this original Lee "et al." paper, two other laboratories have confirmed Pro8-OT and documented additional oxytocin structural variants in this primate taxon. Vargas-Pinilla "et al." sequenced the coding regions of the OXT gene in other genera in new world primates and identified the following variants in addition to Leu8- and Pro8-OT: Ala8-OT, Thr8-OT, and Val3/Pro8-OT. Ren "et al." identified a variant further, Phe2-OT in howler monkeys.
Postpartum bleeding
Oxytocin helps the uterus to contract quickly and the contractions to last for longer. It is the first line treatment for PPH when its cause is the uterus not contracting well. A combination of syntocinon and ergometrine is commonly used as part of active management of the third stage of labour. This is called syntometrine. Syntocinon alone lowers the risk of PPH. Based on limited research available it is unclear whether syntocinon or syntometrine is most effective in preventing PPH but adverse effects are worse with syntometrine making syntocinon a more attractive option. Ergometrine also has to be kept cool and in a dark place so that it is safe to use. It does reduce the risk of PPH by improving the tone of the uterus when compared with no treatment however it has to be used with caution due to its effect raising blood pressure and causing worse after pains.
Inositol nicotinate
Inositol nicotinate, also called inositol hexanicotinate, is marketed in the United States as a "no-flush niacin" dietary supplement. Flushing, in physiology, essentially means that epidermal tissues have become reddened, such as when the skin is irritated from the histamine responses related to an allergic reaction, or from recent physical exercise, or even from anger or embarrassment. This form of niacin is supposed to reduce or prevent flushing by being broken down into the metabolites niacin (nicotinic acid) and inositol at a slow rate.
C. Sue Carter
Carter studies social bonding, male and female parental behavior, the social control of stress reactivity and the social control of reproduction, often using animal models such as the socially monogamous prairie vole. Carter’s research focuses on neuropeptide and steroid hormones, including oxytocin, vasopressin, corticotropin-releasing hormone, and estrogen. Her research program has discovered important new developmental functions for oxytocin and vasopressin, and implicated these hormones in the regulation of long-lasting neural and effects of early social experiences. She also has a long-standing concern regarding the consequences of medical manipulations for human development and parent-child interactions, including the use of “pitocin” to induce labor and consequences of breast feeding for the mother and child. Most recently she has been examining the role of oxytocin and vasopressin in mental disorders such as autism, schizophrenia, anxiety and depression. Carter is also known for research on the physiological basis of social behavior, including studies that implicated oxytocin, vasopressin and hormones of the hypothalamic-pituitary-adrenal (“stress”) axis in the traits of monogamy including pair-bond formation. She pioneered the physiological study of socially monogamous mammals, including the prairie vole. In collaboration with Lowell Getz, Carter documented the occurrence of social monogamy in prairie voles. Her studies in rodents helped to lay the foundation for the studies of behavioral and developmental effects of oxytocin and vasopressin in humans which are in progress. In collaboration with Margaret Altemus she conducted some of the first studies documenting the importance of breast-feeding in the regulation of maternal physiology.
Endocrinology of parenting
However, experimental results are less conclusive. Nulliparous mice do not respond to pup calls, but when administered with oxytocin, they do. A similar study conducted by Holmon and Goy tested nulliparous rhesus females, where post injection did not elicit a drastic response to infants, however there was a notable change in the adult's behavior, including increased proximity and touching. Oxytocin is more often described as a hormone that facilitates bonding and not one that directly increases care. Also, the mice were responding to pup calls and the rhesus macaque infants weren't necessarily providing cues. Similar to the explanation provided for the variation in estrogen and progesterone, rhesus macaques live in drastically different environments. Saltzman proposes that this is due to primates living socially and having a slower developmental trajectory, in which learning is more important.
Oxytetracycline
Oxytetracycline is also used to treat acne, due to its activity against the bacteria on the skin that cause acne ("Propionibacterium acnes"). It is used to treat flare-ups of chronic bronchitis, due to its activity against the bacteria usually responsible, "Haemophilus influenzae". Oxytetracycline may also be used to treat other rarer infections, such as those caused by a group of micro-organisms called rickettsiae ("e.g.", Q fever). To make sure the bacteria causing an infection are susceptible to it, a tissue sample is usually taken, for example a swab from the infected area, or a urine or blood sample.
Oxylipin
Oxylipins in animals, referred to as eicosanoids (Greek icosa; twenty) because of their formation from twenty-carbon essential fatty acids, have potent and often opposing effects on e.g. smooth muscle (vasculature, myometrium) and blood platelets. Certain eicosanoids (leukotrienes B4 and C4) are proinflammatory whereas others (resolvins, protectins) are antiinflammatory and are involved in the resolution process which follows tissue injury. Plant oxylipins are mainly involved in control of ontogenesis, reproductive processes and in the resistance to various microbial pathogens and other pests.
Oxytocin receptor
The receptors for oxytocin (OXTR) have genetic differences with varied effects on individual behavior. The polymorphism (rs53576) occurs on the third intron of OXTR in three types: GG, AG, AA. The GG allele is connected with oxytocin levels in people . A-allele carrier individuals are associated with more sensitivity to stress, fewer social skills, and more mental health issues than the GG-carriers.
In-group favoritism
Oxytocin is not only correlated with the preferences of individuals to associate with members of their own group, but it is also evident during conflicts between members of different groups. During conflict, individuals receiving nasally administered oxytocin demonstrate more frequent defense-motivated responses toward in-group members than out-group members. Further, oxytocin was correlated with participant desire to protect vulnerable in-group members, despite that individual's attachment to the conflict. Similarly, it has been demonstrated that when oxytocin is administered, individuals alter their subjective preferences in order to align with in-group ideals over out-group ideals. These studies demonstrate that oxytocin is associated with intergroup dynamics.
Human bonding
There is evidence in a variety of species that the hormones oxytocin and vasopressin are involved in the bonding process, and in other forms of prosocial and reproductive behavior. Both chemicals facilitate pair bonding and maternal behavior in experiments on laboratory animals. In humans, there is evidence that oxytocin and vasopressin are released during labor and breastfeeding, and that these events are associated with maternal bonding. According to one model, social isolation leads to stress, which is associated with activity in the hypothalamic-pituitary-adrenal axis and the release of cortisol. Positive social interaction is associated with increased oxytocin. This leads to bonding, which is also associated with higher levels of oxytocin and vasopressin, and reduced stress and stress-related hormones.
Oxygen–hemoglobin dissociation curve
Myo-inositol trispyrophosphate (ITPP), also known as OXY111A, is an inositol phosphate that causes a rightward shift in the oxygen hemoglobin dissociation curve through allosteric modulation of hemoglobin within red blood cells. It is an experimental drug intended to reduce tissue hypoxia. The effects appear to last roughly as long as the affected red blood cells remain in circulation.
Oxytocin receptor
The oxytocin receptor, also known as OXTR, is a protein which functions as receptor for the hormone and neurotransmitter oxytocin. In humans, the oxytocin receptor is encoded by the "OXTR" gene which has been localized to human chromosome 3p25.
Animal sexual behaviour
Research on oxytocin's role in the animal brain suggests that it plays less of a role in behaviours of love and affection than previously believed. "When oxytocin was first discovered in 1909, it was thought mostly to influence a mother’s labour contractions and milk let-down. Then, in the 1990s, research with prairie voles found that giving them a dose of oxytocin resulted in the formation of a bond with their future mate (Azar, 40)." Oxytocin has since been treated by the media as the sole player in the "love and mating game" in mammals. This view, however, is proving to be false as, "most hormones don’t influence behaviour directly. Rather, they affect thinking and emotions in variable ways (Azar, 40)." There is much more involved in sexual behaviour in the mammalian animal than oxytocin and vasopressin can explain.
Carbetocin
During pregnancy, the synthesis of oxytocin receptors in the uterus greatly increases, reaching a peak during labor and delivery. Consequently, the administration of carbetocin or another oxytocin analog during or immediately following birth will have increased uterotonic and contractile effect. The application of carbetocin does not affect a non-pregnant uterus with lower oxytocin receptor expression. Carbetocin also functions to thicken the blood, further preventing post-partum hemorrhage. Carbetocin should not be used to induce or augment labor since it could cause cardiac or respiratory distress to mother or infant.
Oxymetholone
Oxymetholone is used for physique- and performance-enhancing purposes by competitive athletes, bodybuilders, and powerlifters.
Neuroendocrinology
Oxytocin and vasopressin (also called anti-diuretic hormone), the two neurohypophysial hormones of the posterior pituitary gland (the neurohypophysis), are secreted from the nerve endings of magnocellular neurosecretory cells into the systemic circulation. The cell bodies of the oxytocin and vasopressin neurons are in the paraventricular nucleus and supraoptic nucleus, respectively, and the electrical activity of these neurons is regulated by afferent synaptic inputs from other brain regions. By contrast, the hormones of the anterior pituitary gland (the adenohypophysis) are secreted from endocrine cells that, in mammals, are not directly innervated, yet the secretion of these hormones (adrenocorticotrophic hormone, luteinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone, prolactin, and growth hormone) remains under the control of the hypothalamus. The hypothalamus controls the anterior pituitary gland via "releasing factors" and "release-inhibiting factors"; these are blood-borne substances [author means via bloodstream and not by the lymphatic system nor air, nor any other modes of transport] released by hypothalamic neurons into blood vessels at the base of the brain, at the median eminence. These vessels, the hypothalamo-hypophysial portal vessels, carry the hypothalamic factors to the anterior pituitary, where they bind to specific receptors on the surface of the hormone-producing cells.
Psychopharmacology
Hypnotics are often used to treat the symptoms of insomnia, or other sleep disorders. Benzodiazepines are still among the most widely prescribed sedative-hypnotics in the United States today. Certain non-benzodiazepine drugs are used as hypnotics as well. Although they lack the chemical structure of the benzodiazepines, their sedative effect is similarly through action on the GABAA receptor. They also have a reputation of being less addictive than benzodiazepines. Melatonin, a naturally-occurring hormone, is often used over the counter (OTC) to treat insomnia and jet lag. This hormone appears to be excreted by the pineal gland early during the sleep cycle and may contribute to human circadian rhythms. Because OTC melatonin supplements are not subject to careful and consistent manufacturing, more specific melatonin agonists are sometimes preferred. They are used for their action on melatonin receptors in the suprachiasmatic nucleus, responsible for sleep-wake cycles. Many barbiturates have or had an FDA-approved indication for use as sedative-hypnotics, but have become less widely used because of their limited safety margin in overdose, their potential for dependence, and the degree of central nervous system depression they induce. The amino-acid L-tryptophan is also available OTC, and seems to be free of dependence or abuse liability. However, it is not as powerful as the traditional hypnotics. Because of the possible role of serotonin in sleep patterns, a new generation of 5-HT antagonists are in current development as hypnotics.
Oxymetholone
Oxymetholone, sold under the brand names Anadrol and Anapolon among others, is an androgen and anabolic steroid (AAS) medication which is used primarily in the treatment of anemia. It is also used to treat osteoporosis, HIV/AIDS wasting syndrome, and to promote weight gain and muscle growth in certain situations. It is taken by mouth.
Side effects of oxymetholone include increased sexual desire as well as symptoms of masculinization like acne, increased hair growth, and voice changes. It can also cause liver damage. The drug is a synthetic androgen and anabolic steroid and hence is an agonist of the androgen receptor (AR), the biological target of androgens like testosterone and dihydrotestosterone (DHT). It has strong anabolic effects and weak androgenic effects.
Oxymetholone was first described in 1959 and was introduced for medical use by 1961. It is used mostly in the United States. In addition to its medical use, oxymetholone is used to improve physique and performance. The drug is a controlled substance in many countries and so non-medical use is generally illicit.
Oxytocin
Oxytocin is not only correlated with the preferences of individuals to associate with members of their own group, but it is also evident during conflicts between members of different groups. During conflict, individuals receiving nasally administered oxytocin demonstrate more frequent defense-motivated responses toward in-group members than out-group members. Further, oxytocin was correlated with participant desire to protect vulnerable in-group members, despite that individual's attachment to the conflict. Similarly, it has been demonstrated that when oxytocin is administered, individuals alter their subjective preferences in order to align with in-group ideals over out-group ideals. These studies demonstrate that oxytocin is associated with intergroup dynamics. Further, oxytocin influences the responses of individuals in a particular group to those of another group. The in-group bias is evident in smaller groups; however, it can also be extended to groups as large as one's entire country leading toward a tendency of strong national zeal. A study done in the Netherlands showed that oxytocin increased the in-group favoritism of their nation while decreasing acceptance of members of other ethnicities and foreigners. People also show more affection for their country's flag while remaining indifferent to other cultural objects when exposed to oxytocin. It has thus been hypothesized that this hormone may be a factor in xenophobic tendencies secondary to this effect. Thus, oxytocin appears to affect individuals at an international level where the in-group becomes a specific "home" country and the out-group grows to include all other countries.Oxytocin is typically remembered for the effect it has on prosocial behaviors, such as its role in facilitating trust and attachment between individuals. Consequently, oxytocin is often referred to as the “love hormone". However, oxytocin has a more complex role than solely enhancing prosocial behaviors. There is consensus that oxytocin modulates fear and anxiety; that is, it does not directly elicit fear or anxiety. Two dominant theories explain the role of oxytocin in fear and anxiety. One theory states that oxytocin increases approach/avoidance to certain social stimuli and the second theory states that oxytocin increases the salience of certain social stimuli, causing the animal or human to pay closer attention to socially relevant stimuli.
Ethnocentrism
Research published by Proceedings of the National Academy of Sciences of the United States of America (PNAS) suggested that ethnocentrism may be mediated by the oxytocin hormone. It was found that in randomized controlled trials "oxytocin creates intergroup bias because oxytocin motivates in-group favoritism and, to a lesser extent, out-group derogation."
Opioid epidemic
Oxycodone was first made available in the United States in 1939. In the 1970s, the FDA classified oxycodone as a Schedule II drug, indicating a high potential for abuse and addiction. In 1996, Purdue Pharma introduced OxyContin, a controlled release formulation of oxycodone. The FDA approved relabeling the reformulated version as abuse-resistant. However, drug users quickly learned how to simply crush the controlled release tablet to swallow, inhale, or inject the high-strength opioid for a powerful morphine-like high. In fact, Purdue's private testing conducted in 1995 determined that 68% of the oxycodone could be extracted from an OxyContin tablet when crushed.
Castles Made of Sand (novel)
Halfway through "Bold as Love" the two male leads agree that one day they will take oxytocin together — the intimacy drug, based on the hormone released to create the bond between mother and baby, or between monogamous reproductive partners. At the opening of the second episode we meet Ax and Sage loved-up, making out on Brighton Beach on an oxytocin high: a shocking development for readers lulled by the sexual conformity of the first volume. Ensuing chapters are devoted to the painful birth-pangs of a passionate rock and roll sexual threesome.
Oxytocin
Oxytocin has peripheral (hormonal) actions, and also has actions in the brain. Its actions are mediated by specific, oxytocin receptors. The oxytocin receptor is a G-protein-coupled receptor that requires magnesium and cholesterol. It belongs to the rhodopsin-type (class I) group of G-protein-coupled receptors.
Ozenoxacin
Ozenoxacin (INN; trade names Ozaenex and Xepi) is a quinolone antibiotic used for the treatment of impetigo. A 1% topical cream is approved for treatment of impetigo in Canada and in the United States.
Aggression
The hormonal neuropeptides vasopressin and oxytocin play a key role in complex social behaviours in many mammals such as regulating attachment, social recognition, and aggression. Vasopressin has been implicated in male-typical social behaviors which includes aggression. Oxytocin may have a particular role in regulating female bonds with offspring and mates, including the use of protective aggression. Initial studies in humans suggest some similar effects.
Oxytocin
Endogenous oxytocin concentrations in the brain have been found to be as much as 1000-fold higher than peripheral levels.
Postpartum bleeding
Oxytocin is typically used right after the delivery of the baby to prevent PPH. Misoprostol may be used in areas where oxytocin is not available. Early clamping of the umbilical cord does not decrease risks and may cause anemia in the baby, thus is usually not recommended.
Oxytocin
Oxytocin is synthesized by corpora lutea of several species, including ruminants and primates. Along with estrogen, it is involved in inducing the endometrial synthesis of prostaglandin F to cause regression of the corpus luteum.
Oxotoxin
Oxotoxins, or oxytoxins, are a group of neurotoxins present in the venom of lynx spiders belonging to the genus "Oxyopes", hence the name "oxytoxin". They are disulfide-rich peptides. Only two types are so far reported from two different species, the larger oxytoxin 1 (OxyTx1) from "Oxyopes kitabensis", and the smaller oxytoxin 2 (OxyTx2) from "Oxyopes lineatus". OxyTx1, the first known oxytoxin, was discovered in 2002. It was found to enhance the lethal efficacy of the spider venom by acting together with oxyopinins. It is composed of 69 amino acid residue, which are cross-linked by five disulfide bridges. It is a large peptide having a molecular mass of 8059.2 Da; but shows the size of 9,109.4 Da due to the presence of disulfide bridges. It is a potent insecticide, but non-toxic to mice up to 1 μg/20-g mouse. It acts synergistically with oxyopinins of the same venom to increase the insecticidal effect.
In-group favoritism
Further, oxytocin influences the responses of individuals in a particular group to those of another group. The in-group bias is evident in smaller groups; however, it can also be extended to groups as large as one's entire country leading toward a tendency of strong national zeal. A study done in the Netherlands showed that oxytocin increased the in-group favoritism of their nation while decreasing acceptance of members of other ethnicities and foreigners. People also show more affection for their country's flag while remaining indifferent to other cultural objects when exposed to oxytocin. It has thus been hypothesized that this hormone may be a factor in xenophobic tendencies secondary to this effect. Thus, oxytocin appears to affect individuals at an international level where the in-group becomes a specific "home" country and the out-group grows to include all other countries.
Vomitoxin
Vomitoxin belongs to a class of mycotoxins (trichothecenes) which are strong inhibitors of protein synthesis; exposure to vomitoxin causes the brain to increase its uptake of the amino acid tryptophan and, in turn, its synthesis of serotonin. Increased levels of serotonin are believed to be responsible for the anorexic effects of DON and other trichothecenes. Irritation of the gastrointestinal tract may also play a role in reducing feed intake, and may also partially explain the high incidence of paraesophageal stomach ulcers observed in sows during feed refusal. In humans DON is extensively glucuronidated and excreted via urine.
Oxypertine
Oxypertine (Equipertine, Forit, Integrin, Lanturil, Lotawin, Opertil) is an antipsychotic used in the treatment of schizophrenia. It was also evaluated for the treatment of anxiety at a dosage of 20 mg per day. Chemically, it is an indole and phenylpiperazine derivative. Like reserpine and tetrabenazine, oxypertine depletes catecholamines, though not serotonin, possibly underlying its neuroleptic efficacy. Its structure is similar to solypertine and milipertine.
Oxytocin receptor
Oxytocin receptors are also present in the central nervous system. These receptors modulate a variety of behaviors, including stress and anxiety, social memory and recognition, sexual and aggressive behaviors, bonding (affiliation) and maternal behavior. (See the oxytocin article for more details.)
Pillow talk
The content of pillow talk typically includes the sexual act itself, stories and confessions, expressions of affection and appreciation, and playful humor. A line of research done on pillow talk has revolved around the hormone known as oxytocin; this "bonding hormone" is related to other effects, such as decreasing stress, decreasing perceptions of social threat, increasing bonding, and increasing the ability to read emotional cues. This hormone has been known to increase in the body proceeding sexual activity between two people that have reached the point of orgasm. The individuals involved in this act of coitus can benefit from this process by opening up in a sense of communication and trust. A study done by Amanda Denes (2012), shows that partners who orgasm are more likely to engage in the act of pillow talk versus partners who do not orgasm.
Demoxytocin
Demoxytocin (INN) (brand names Sandopart, Odeax, Sandopral), also known as desaminooxytocin or deaminooxytocin, as well as 1-(3-mercaptopropanoic acid)oxytocin ([Mpa]OT), is an oxytocic peptide drug that is used to induce labor, promote lactation, and to prevent and treat puerperal (postpartum) mastitis (breast inflammation). Demoxytocin is a synthetic analogue of oxytocin and has similar activities, but is more potent and has a longer half-life in comparison. Unlike oxytocin, which is given via intravenous injection, demoxytocin is administered as a buccal tablet formulation.
Oxytocin
The biologically active form of oxytocin, commonly measured by RIA and/or HPLC techniques, is also known as the octapeptide "oxytocin disulfide" (oxidized form), but oxytocin also exists as a reduced straight-chain (non-cyclic) dithiol nonapeptide called oxytoceine. It has been theorized that oxytoceine may act as a free radical scavenger, as donating an electron to a free radical allows oxytoceine to be re-oxidized to oxytocin via the dehydroascorbate / ascorbate redox couple.
Ofloxacin
Ofloxacin is an antibiotic useful for the treatment of a number of bacterial infections. When taken by mouth or injection into a vein this includes pneumonia, cellulitis, urinary tract infections, prostatitis, plague and certain types of infectious diarrhea. Other uses, along with other medications, include multidrug resistant tuberculosis. An eye drop may be used for a superficial bacterial infection of the eye and an ear drop may be used for otitis media when there is a hole in the ear drum.
When taken by mouth common side effects include vomiting, diarrhea, headache, and rash. Other serious side effect include tendon rupture, numbness due to nerve damage, seizures, and psychosis. Use in pregnancy is typically not recommended. Ofloxacin is in the fluoroquinolone family of medications. It works by interfering with the bacterium's DNA.
Ofloxacin was patented in 1980 and approved for medical use in 1985. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Ofloxacin is available as a generic medication. The wholesale cost in the developing world is about US$3.27 per month. In the United States a course of treatment costs about $50–100.
Oxytocin (medication)
People using oxytocin show improved recognition for positive social cues over threatening social cues and improved recognition of fear. However, oxytocin has also the potential for being abused in confidence tricks.
Oxytocin
The two genes are believed to result from a gene duplication event; the ancestral gene is estimated to be about 500 million years old and is found in cyclostomata (modern members of the Agnatha).
Oxytocin
Estrogen has been found to increase the secretion of oxytocin and to increase the expression of its receptor, the oxytocin receptor, in the brain. In women, a single dose of estradiol has been found to be sufficient to increase circulating oxytocin concentrations.
Oxotremorine
Oxotremorine (i.e. oxo M) is a parasympathomimetic drug that acts as a selective muscarinic acetylcholine receptor agonist.
Social cue
Oxytocin has been named "the social hormone". Research done on rats provide strong evidence that social contact enhances oxytocin levels in the brain which then sets the stage for social bonds. In recent years it has been found that inhaling oxytocin through the nasal passage increases trust toward strangers and increases a person's ability to perceive social cues. Activation of face-induced amygdala was found to be increased by oxytocin in women. There have been findings that oxytocin increases occurrence of attention shifts to the eye region of a face which suggests that it alters the readiness of the brain to socially meaningful stimuli. Dopamine neuron from the ventral tegmental area codes the salience of social as well as nonsocial stimuli. Bartz and his colleagues found that the effects of oxytocin is person-dependent, meaning that every individual will be affected differently, especially those who have trouble in social situations. Research done by Groppe and colleagues supports that motivational salience of social cues is enhanced by oxytocin. Oxytocin has been found to increase cues that are socially relevant.
Opioid epidemic
Opioids are a diverse class of moderately strong painkillers, including oxycodone (commonly sold under the trade names OxyContin and Percocet), hydrocodone (Vicodin, Norco), and a very strong painkiller, fentanyl, which is synthesized to resemble other opiates such as opium-derived morphine and heroin. The potency and availability of these substances, despite their high risk of addiction and overdose, have made them popular both as medical treatments and as recreational drugs. Due to their sedative effects on the part of the brain which regulates breathing, the respiratory center of the medulla oblongata, opioids in high doses present the potential for respiratory depression, and may cause respiratory failure and death.
Oxytocin
Oxytocin is known to be metabolized by the oxytocinase, leucyl/cystinyl aminopeptidase. Other oxytocinases are also known to exist. Amastatin, bestatin (ubenimex), leupeptin, and puromycin have been found to inhibit the enzymatic degradation of oxytocin, though they also inhibit the degradation of various other peptides, such as vasopressin, met-enkephalin, and dynorphin A.
Lipo-oxytocin-1
Lipo-oxytocin-1 (LOT-1) is a synthetic peptide and derivative of oxytocin that acts as an agonist of the oxytocin receptor. The lipidation strategy was applied to oxytocin to create a new peptide with improved pharmacokinetics. LOT-1 consists of oxytocin conjugated with two palmitoyl groups. After adjusting for molecular weight (LOT-1 is ~1.5x the weight of oxytocin), oxytocin and LOT-1 are equipotent. In addition, LOT-1 appears to have a significantly longer duration of effect relative to that of oxytocin. It has yet to be determined whether LOT-1 possesses improved blood-brain-barrier permeability relative to oxytocin.
Anxiolytic
Opioids are drugs that are usually only prescribed for their painkilling properties, but some research is beginning to find that some varieties are effective at treating depression, obsessive compulsive disorder, and other ailments often associated with or caused by anxiety. They have a very high potential for abuse and have one of the highest addiction rates for all drugs. Many people become addicted to these drugs because they are so effective at blocking emotional pain, including anxiety. Similarly to alcohol, people with anxiety disorders are more likely to become addicted to opioids due to their anxiolytic effect. These drugs range from the commonly prescribed hydrocodone, to the often illegal heroin, and all the way to much more potent varieties like fentanyl often used in trauma or end of life pain management. Most people purchasing these drugs illegally are seeking them out to get a euphoric like high, but many others seek them out because they are so effective at reducing both physical pain and emotional pain.
Romance (love)
Another topic of controversy in the field of romantic relationships is that of domestic abuse. Following the theory that romantic love evolved as a byproduct of survival, it can be said that in some instances, it has turned into a maladaptation. Oxytocin is a neurophysical hormone produced in the brain. It is known to cause a decrease in stress response. It also can cause an increase in feelings of attachment. In the beginning stages of a romantic relationship, OT levels surge and then remain relatively stable over the duration of the relationship. The higher the surge of OT, the greater the likelihood is of partners staying together. It plays an important role in increasing positive interpersonal behaviors such as trust, altruism, empathy, etc. This response is not universal and can in fact, cause the opposite to occur depending on environment and individual. Individuals ranked high in rejection sensitivity exhibited aggressive tendencies and decreased willingness for cooperation, indicating a link between oxytocin and relationship maintenance.
Childbirth
Augmentation is the process of stimulating the uterus to increase the intensity and duration of contractions after labour has begun. Several methods of augmentation are commonly been used to treat slow progress of labour (dystocia) when uterine contractions are assessed to be too weak. Oxytocin is the most common method used to increase the rate of vaginal delivery. The World Health Organization recommends its use either alone or with amniotomy (rupture of the amniotic membrane) but advises that it must be used only after it has been correctly confirmed that labour is not proceeding properly if harm is to be avoided. The WHO does not recommend the use of antispasmodic agents for prevention of delay in labour.
Endocrinology of parenting
In some studies on females across species, estrogen and progesterone prepartum is also related to oxytocin. Although, the relationships between these hormones is similar across species, there is variation in the degree to how oxytocin effects behavior. For example, in some species, like rats, an increase in oxytocin greatly increases interactions with infants, but an increase in oxytocin in macaques only mildly increased interactions. However, the importance here is that oxytocin increased interactions in all of the relevant cited studies for females, as well as the majority of studies cited for males.
L-368,899
L-368,899 is a drug used in scientific research which acts as a selective antagonist of the oxytocin receptor, with good selectivity over the related vasopressin receptors. Unlike related drugs such as the peripherally selective L-371,257, the oral bioavailabity is high and the brain penetration of L-368,899 is rapid, with selective accumulation in areas of the limbic system. This makes it a useful tool for investigating the centrally mediated roles of oxytocin, such as in social behaviour and pair bonding, and studies in primates have shown L-368,899 to reduce a number of behaviours such as food sharing, sexual activity and caring for infants, demonstrating the importance of oxytocinergic signalling in mediating these important social behaviours.
Biomarkers of diabetes
Oxytocin (OXT), a hormone most commonly associated with labor and lactation, may have a wide variety of physiological and pathological functions, which makes Oxytocin and its receptor potential targets for drug therapy.
OXT may have positive metabolic effects; this is based on the change in glucose metabolism, lipid profile, and insulin sensitivity. It may modify glucose uptake and insulin sensitivity both through direct and indirect effects. It may also cause regenerative changes in diabetic pancreatic islet cells. So, the activation of the OXT receptor pathway by infusion of OXT, OXT analogues, or OXT agonists may represent a promising approach for the management of obesity and related metabolic diseases as well as diabetes and its complications.
Oxytocin/ergometrine
Prostaglandins increase the effect of oxytocin and vice versa. The contractions should be carefully monitored if oxytocin is given after a prostaglandin dose.
Isotretinoin
Isotretinoin, also known as 13-"cis"-retinoic acid (and colloquially referred to by its former brand name Accutane or Roaccutane), is a medication primarily used to treat severe acne. Rarely, it is also used to prevent certain skin cancers (squamous-cell carcinoma), and in the treatment of other cancers. It is used to treat harlequin-type ichthyosis, a usually lethal skin disease, and lamellar ichthyosis. It is a retinoid, meaning it is related to vitamin A, and is found in small quantities naturally in the body. Its isomer, tretinoin, is also an acne drug.
Optic nerve hypoplasia
Oxytocin is also produced in the posterior pituitary gland. Though best known for its role in childbirth and lactation, oxytocin has also been found to have a role in human bonding, increase in trust, and decrease in fear.
Neurohypophysial hormone
Oxytocin mediates contraction of the smooth muscle of the uterus and mammary gland, while vasopressin has antidiuretic action on the kidney, and mediates vasoconstriction of the peripheral vessels. Due to the similarity of the two hormones, there is cross-reaction: oxytocin has a slight antidiuretic function, and high levels of AVP can cause uterine contractions. In common with most active peptides, both hormones are synthesised as larger protein precursors that are enzymatically converted to their mature forms.
Oxybutynin
Oxybutynin (brand names Ditropan, Lyrinel XL, Lenditro , Driptane , Uripan (Middle East)) is an anticholinergic medication used to relieve urinary and bladder difficulties, including frequent urination and inability to control urination (urge incontinence), by decreasing muscle spasms of the bladder. It is also given to help with symptoms associated with kidney stones.
Romance (love)
In the search for the root of intimate partner violence, intranasal oxytocin was administered to a control group and a group of participants with aggressive tendencies. Participants were then surveyed on how willing they were to engage in 5 behaviors towards their romantic partner. What they found was that oxytocin increased IPV inclinations only among the participants with a predisposition towards aggressive tendencies. Oxytocin decreases trust and prosocial behavior in individuals with interpersonal difficulties. This, coupled with its role in relationship maintenance, illustrates that oxytocin serves to instill a sense of territoriality and protectiveness towards a mate.
Oxytocin
The peripheral actions of oxytocin mainly reflect secretion from the pituitary gland. The behavioral effects of oxytocin are thought to reflect release from centrally projecting oxytocin neurons, different from those that project to the pituitary gland, or that are collaterals from them. Oxytocin receptors are expressed by neurons in many parts of the brain and spinal cord, including the amygdala, ventromedial hypothalamus, septum, nucleus accumbens, and brainstem.
In the prairie vole, oxytocin released into the brain of the female during sexual activity is important for forming a pair bond with her sexual partner. Vasopressin appears to have a similar effect in males. Oxytocin has a role in social behaviors in many species, so it likely also does in humans. In a 2003 study, both humans and dog oxytocin levels in the blood rose after five to 24 minutes of a petting session. This possibly plays a role in the emotional bonding between humans and dogs.
Oxygen
Uptake of from the air is the essential purpose of respiration, so oxygen supplementation is used in medicine. Treatment not only increases oxygen levels in the patient's blood, but has the secondary effect of decreasing resistance to blood flow in many types of diseased lungs, easing work load on the heart. Oxygen therapy is used to treat emphysema, pneumonia, some heart disorders (congestive heart failure), some disorders that cause increased pulmonary artery pressure, and any disease that impairs the body's ability to take up and use gaseous oxygen.
Nipple stimulation
Oxytocin is linked to sexual arousal and pair bonding, but researchers are divided on whether breastfeeding commonly incites sexual feelings. Nipple erection may also result during sexual arousal, or during breastfeeding; both are caused by the release of oxytocin. Nipple erection is due to the contraction of smooth muscle under the control of the autonomic nervous system, and is a product of the pilomotor reflex which causes goose bumps. A survey in 2006 found that sexual arousal in about 82% of young females and 52% of young males occurs or is enhanced by direct stimulation of nipples, with only 7–8% reporting that it decreased their arousal.
Human bonding
A study in 2003, by the U.S. Department of Defense, based on human-animal bonding determined that there was an improvement and enrichment of life when animals were closely involved with humans. The study tested blood levels and noticed a rise in Oxytocin in humans and animals which participated; Oxytocin has the ability to lower stress, heart rate, and fear levels in humans and animals.
Oxytocin (medication)
One IU of oxytocin is the equivalent of about 2 μg or mcg of pure peptide.Its uterine-contracting properties were discovered by British pharmacologist Sir Henry Hallett Dale in 1906. And its milk ejection property was described by Ott and Scott in 1910 and by Schafer and Mackenzie in 1911.
Oxanamide
Oxanamide (Quiactin) is an anxiolytic and muscle relaxant which can produce sedative and hypnotic effects in sufficiently high doses. An uncontrolled trial on patients treated in a clinical gynecology practice published in 1959 found that oxanamide was efficacious in the treatment of anxiety resulting from premenstrual syndrome, menopause, and various other causes, with minimal sedation or other side effects.
Fluoxetine
Fluoxetine is frequently used to treat major depressive disorder, obsessive–compulsive disorder (OCD), post-traumatic stress disorder (PTSD), bulimia nervosa, panic disorder, premenstrual dysphoric disorder, and trichotillomania. It has also been used for cataplexy, obesity, and alcohol dependence, as well as binge eating disorder. It has also been tried as a treatment for autism spectrum disorders with moderate success in adults.
Oxycyte
When used as an intravenous emulsion, Oxycyte can carry as much as five times more oxygen than hemoglobin, making it an effective means of transporting oxygen to tissues and carrying carbon dioxide to the lungs for disposal. Like all PFC-based products, Oxycyte is not a complete blood substitute.
Niacin
Prostaglandin (PGD) is the primary cause of the flushing reaction, with serotonin appearing to have a secondary role in this reaction. The effect is mediated by prostaglandin E2 and D2 due to GPR109A activation of epidermal Langerhans cells and keratinocytes. Langerhans cells use cyclooxygenase type 1 (COX-1) for PGE2 production and are more responsible for acute flushing, while keratinocytes are COX-2 dependent and are in active continued vasodilation. Flushing was often thought to involve histamine, but histamine has been shown not to be involved in the reaction.
Misoprostol
Oxytocin has long been used as the standard agent for labor induction, but does not work well when the cervix is not yet ripe. Misoprostol also may be used in conjunction with oxytocin.
Childbirth
During the later stages of gestation there is an increase in abundance of oxytocin, a hormone that is known to evoke feelings of contentment, reductions in anxiety, and feelings of calmness and security around the mate. Oxytocin is further released during labour when the fetus stimulates the cervix and vagina, and it is believed that it plays a major role in the bonding of a mother to her infant and in the establishment of maternal behavior. The act of nursing a child also causes a release of oxytocin.
Endocrinology of parenting
Oxytocin in human females is associated with the level of physical affection and bonding. Feldman (2010) found that mothers who displayed “high affectionate contact” had increased oxytocin levels post interaction, but not mothers who displayed “low affectionate contact.” Oxytocin is believed to provide a feedback loop, meaning that maternal-infant contact increases oxytocin and oxytocin increases maternal behavior and facilitates bonding. In one study oxytocin also played a role on mother reported attachment to her fetus.
In-group favoritism
Race can be used as an example of in-group and out-group tendencies because society often categorizes individuals into groups based on race (Caucasian, African American, Latino, etc.). One study that examined race and empathy found that participants receiving nasally administered oxytocin had stronger reactions to pictures of in-group members making pained faces than to pictures of out-group members with the same expression. This shows that oxytocin may be implicated in our ability to empathize with individuals of different races, with individuals of one race potentially biased towards helping individuals of the same race than individuals of another race when they are experiencing pain.
Sexual motivation and hormones
The hormones oxytocin and vasopressin are implicated in regulating both male and female sexual motivation. Oxytocin is released at orgasm and is associated with both sexual pleasure and the formation of emotional bonds. Based on the pleasure model of sexual motivation, the increased sexual reproduction pleasure that occurs following oxytocin release may encourage motivation to engage in future sexual reproduction activities. Emotional closeness can be an especially strong predictor of sexual motivation in females and insufficient oxytocin release may subsequently diminish sexual reproduction arousal and motivation in females.
Oxytocin receptor
The OXTR protein belongs to the G-protein coupled receptor family, specifically G, and acts as a receptor for oxytocin. Its activity is mediated by G proteins that activate several different second messenger systems.
Obsessive–compulsive disorder
From the observation of the efficacy of antidepressants in OCD, a serotonin hypothesis of OCD has been formulated. Studies of peripheral markers of serotonin, as well as challenges with proserotonergic compounds have yielded inconsistent results, including evidence pointing towards basal hyperactivity of serotonergic systems. Serotonin receptor and transporter binding studies have yielded conflicting results, including higher and lower serotonin receptor 5-HT2A and serotonin transporter binding potentials that were normalized by treatment with SSRIs. Despite inconsistencies in the types of abnormalities found, evidence points towards dysfunction of serotonergic systems in OCD. Orbitofrontal cortex overactivity is attenuated in people who have successfully responded to SSRI medication, a result believed to be caused by increased stimulation of serotonin receptors 5-HT2A and 5-HT2C. A complex relationship between dopamine and OCD has been observed. Although antipsychotics, which act by antagonizing dopamine receptors may improve some cases of OCD, they frequently exacerbate others. Antipsychotics, in the low doses used to treat OCD, may actually increased the release of dopamine in the prefrontal cortex, through inhibiting autoreceptors. Further complicating things is the efficacy of amphetamines, decreased dopamine transporter activity observed in OCD, and low levels of D2 binding in the striatum. Furthermore, increased dopamine release in the nucleus accumbens after deep brain stimulation correlates with improvement in symptoms, pointing to reduced dopamine release in the striatum playing a role in generating symptoms.
Oxycodone/aspirin
Oxycodone/aspirin (trade name Percodan) is a combination drug marketed by Endo Pharmaceuticals. It is a tablet containing a mixture of 325 mg (5 grains) of aspirin and 4.8355 mg of oxycodone HCl (equivalent to 4.3346 mg of oxycodone as the free base); it is an opioid/non-opioid combination used to treat moderate to moderately severe pain. The safety of the combination during pregnancy has not been established, although aspirin is generally contraindicated during pregnancy, and the drug has been placed in pregnancy category D. Inactive ingredients include D&C Yellow 10, FD&C Yellow 6, microcrystalline cellulose, and corn starch. Percodan was first marketed by DuPont Pharmaceuticals and prescribed in the United States in 1950. Once a widely prescribed painkiller, it has largely been replaced by alternative oxycodone compounds containing paracetamol (acetaminophen) instead of aspirin, such as Percocet.
Oxametacin
Oxametacin (or oxamethacin) is a non-steroidal anti-inflammatory drug.
Xanthine oxidase inhibitor
A xanthine oxidase inhibitor is any substance that inhibits the activity of xanthine oxidase, an enzyme involved in purine metabolism. In humans, inhibition of xanthine oxidase reduces the production of uric acid, and several medications that inhibit xanthine oxidase are indicated for treatment of hyperuricemia and related medical conditions including gout. Xanthine oxidase inhibitors are being investigated for management of reperfusion injury.
Phycocyanin
Excess oxygen in the brain generates Reactive Oxygen Species (ROS). ROS causes damages to brain neurons, leading to strokes. C-phycocyanin scavenges hydrogen peroxide, a type of ROS species, from the inside of astrocyte, reducing oxidative stress. Astrocytes also increase the production of growth factors like BDNF and NDF, therefore, enhance nerve regeneration. C-PC also prevents astrogliosis and glial inflammation.
Carbetocin
Carbetocin functions as an agonist at peripheral oxytocin receptors, particularly in the myometrium, with lesser affinity for myopepithelial cells. Oxytocin receptors are G protein-coupled and their mechanism of action involves second messengers and the production of inositol phosphates. Carbetocin mimics this mechanism. Binding for carbetocin and other oxytocin agonists has been shown to be nonselective at the extracellular N-terminus and loops E2 and E3. While the oxytocin receptor shows equal affinity for oxytocin and carbetocin, the biological effect of carbetocin is almost 50% that of endogenous or exogenous oxytocin. Carbetocin has a much longer lasting effect than oxytocin, necessitating only a single dose. Carbetocin inhibits endogenous oxytocin release, interrupting the uterine feedback loop with the hypothalamus and decreasing both central and peripheral release of oxytocin.
Sexual desire and intimate relationships
Much like the opioids mentioned above, the neuropeptide oxytocin has been shown to be extremely affective in the conditioning effects involved in the formation of stable preferences for places, stimuli and other beings. Studies have shown that women specifically not only show greater sensitivity to the release of oxytocin during sexual activity than men, but it has been suggested a correlation exists between oxytocin release and orgasm intensity, which may explain why women generally associate stronger interconnectivity between love and sexual desire.
Marinus van IJzendoorn
In humans, oxytocin has been shown to be associated with delivery, mood regulation, sexual functioning and parenting behaviours. Emerging studies are showing an increasing link between oxytocin levels in humans and parent-child relationships. One idea is that increased oxytocin levels facilitates postnatal parental behaviour and the formation of an emotional bond between parent and infant, in mothers and fathers alike, by acting to reduce anxiety and ameliorate responses to external stresses. Parents who have a less anxious state of mind are able to increase their focus on infant care, improve mood, and facilitate the capacity to read non-verbal infant cues and stimulate the social learning and reward system in response to infant cues. Although there are strong animal models for the role of oxytocin in parental behaviour, one of the key questions in the development of a psychobiology of human care-giving and attachment is the degree to which the considerable variation in parenting can be accounted for through similar biological mechanisms such as the moderating role of the oxytocin receptor gene (OXTR) polymorphisms and experimentally induced oxytocin levels.
Van IJzendoorn and colleagues conducted several correlational studies documenting the role of OXTR in parenting, and carried out various randomized control trials showing that oxytocin enhances male and female sensitivity to child signals, in natural play settings as well as with a cry test, using behavioural assessments, EEG/ERP, and fMRI. A meta-analysis of experimental studies with intranasal oxytocin administration was conducted showing that feelings of trust are elevated and that the expected lowering of out-group trust was not confirmed.
Oxidopamine
The main use for oxidopamine in scientific research is to induce Parkinsonism in laboratory animals such as mice, rats and monkeys, in order to develop and test new medicines and treatments for Parkinson's disease. In order to induce this condition in animals, around 70% of the dopaminergic neurons in the substantia nigra of the brain must be destroyed, and this is achieved either with oxidopamine or MPTP. Both these agents likely destroy neurons by generating reactive oxygen species such as superoxide radical. Oxidopamine toxicity in neonatal rodents is also used as an animal model for the Lesch-Nyhan syndrome.
Oxytrex
Oxytrex is an investigational drug currently in clinical trials. It combines the well known opioid agonist oxycodone in the treatment of pain with an ultra-low dose of naltrexone, an opioid antagonist. Naltrexone can have markedly different pharmacokinetics at ultra-low doses which may include, the attenuation of a pre-established opioid tolerance, the prevention of tolerance from the oxycodone in the formulation, and the possible amplification of oxycodone. It is being developed by "Pain Therapeutics, Inc." for the treatment of severe chronic pain.
Sexual intercourse
In humans, sexual intercourse and sexual activity in general have been reported as having health benefits as varied as increased immunity by increasing the body's production of antibodies and subsequent lower blood pressure, and decreased risk of prostate cancer. Sexual intimacy and orgasms increase levels of the hormone oxytocin (also known as "the love hormone"), which can help people bond and build trust. Oxytocin is believed to have a more significant impact on women than on men, which may be why women associate sexual attraction or sexual activity with romance and love more than men do. A long-term study of 3,500 people between ages 18 and 102 by clinical neuropsychologist David Weeks indicated that, based on impartial ratings of the subjects' photographs, sex on a regular basis helps people look significantly chronologically younger.