by mutation of V2 receptor or AQP) leads to diabetes insipidus, a condition featuring hypernatremia (increased blood sodium concentration), polyuria (excess urine production), and polydipsia (thirst). Excess
Syndrome of Inappropriate Antidiuretic Hormone secretion (SIADH) in turn can be caused by a number of problems. Some forms of cancer can cause SIADH, particularly small cell lung carcinoma but also a number of other tumors. A variety of diseases affecting the brain or the lung (infections, bleeding) can be the driver behind SIADH. A number of drugs have been associated with SIADH, such as certain antidepressants (serotonin reuptake inhibitors and tricyclic antidepressants), the anticonvulsant carbamazepine, oxytocin (used to induce and stimulate labor), and the chemotherapy drug vincristine. It has also been associated with fluoroquinolones (including ciprofloxacin and moxifloxacin). Finally, it can occur without a clear explanation. Hyponatremia can be treated pharmaceutically through the use of vasopressin receptor antagonists. History
Vasopressin was elucidated and synthesized for the first time by Vincent du Vigneaud. Animal studies
Evidence for an effect of AVP on monogamy vs polygamy comes from experimental studies in several species, which indicate that the precise distribution of vasopressin and vasopressin receptors in the brain is associated with species-typical patterns of social behavior. In particular, there are consistent differences between monogamous species and polygamous species in the distribution of AVP receptors, and sometimes in the distribution of vasopressin-containing axons, even when closely related species are compared. Human studies
Vasopressin has shown nootropic effects on pain perception and cognitive function.
Human vasopressin, also called antidiuretic hormone (ADH),   arginine vasopressin (AVP) or argipressin, is a hormone synthesized from the AVP gene as a peptide prohormone in neurons in the hypothalamus, and is converted to AVP. It then travels down the axon terminating in the posterior pituitary, and is released from vesicles into the circulation in response to extracellular fluid hypertonicity (hyperosmolality). AVP has two primary functions. First, it increases the amount of solute-free water reabsorbed back into the circulation from the filtrate in the kidney tubules of the nephrons. Second, AVP constricts arterioles, which increases peripheral vascular resistance and raises arterial blood pressure.A third function is possible. Some AVP may be released directly into the brain from the hypothalamus, and may play an important role in social behavior, sexual motivation and pair bonding, and maternal responses to stress.Vasopressin induces differentiation of stem cells into cardiomyocytes and promotes heart muscle homeostasis.It has a very short half-life, between 16 and 24 minutes. Physiology
Function
Vasopressin regulates the  tonicity of body fluids. It is released from the posterior pituitary in response to hypertonicity and causes the kidneys to reabsorb solute-free water and return it to the circulation from the tubules of the nephron, thus returning the tonicity of the body fluids toward normal. An incidental consequence of this renal reabsorption of water is concentrated urine and reduced urine volume. AVP released in high concentrations may also raise blood pressure by inducing moderate vasoconstriction. AVP also may have a variety of neurological effects on the brain.