Goserelin, sold under the brand name Zoladex among others, is a medication which is used to suppress production of the sex hormones (testosterone and estrogen), particularly in the treatment of breast and prostate cancer. It is an injectable gonadotropin releasing hormone agonist (GnRH agonist). Structurally, it is a decapeptide. It is the natural GnRH decapeptide with two substitutions to inhibit rapid degradation. Goserelin stimulates the production of the sex hormones testosterone and estrogen in a non-pulsatile (non-physiological) manner. This causes the disruption of the endogenous hormonal feedback systems, resulting in the down-regulation of testosterone and estrogen production. It was patented in 1976 and approved for medical use in 1987. It is on the World Health Organizations List of Essential Medicines. Medical uses
Goserelin is used to treat hormone-sensitive cancers of the breast (in pre- and peri-menopausal women) and prostate, and some benign gynaecological disorders (endometriosis, uterine fibroids and endometrial thinning). In addition, goserelin is used in assisted reproduction and in the treatment of precocious puberty. It may also be used in the treatment of male-to-female transgender people and is favoured above other anti-androgens in some countries, such as the UK. It is available as a 1-month depot and a long-acting 3-month depot. Goserelin is administered by subcutaneous injection as an implant every 28 days for the duration of treatment. Side effects
Goserelin may cause a temporary increase in bone pain and symptoms of prostatic cancer during the first few weeks of treatment.
This means a defective gene responsible for the disorder is located on an autosome, and two copies of the defective gene (one inherited from each parent) are required in order to be born with the disorder. The parents of an individual with an autosomal recessive disorder both carry one copy of the defective gene, but usually do not experience any signs or symptoms of the disorder. Pathophysiology
At present, no specific enzyme deficiency nor genetic mutation has been implicated as the cause of hypertryptophanemia. Several known factors regarding tryptophan metabolism and kynurenines, however, may explain the presence of behavioral abnormalities seen with the disorder.Tryptophan is an essential amino acid, and is required for protein synthesis. Aside from this crucial role, the remainder of tryptophan is primarily metabolized along the kynurenine pathway in most tissues, including those of the brain and central nervous system.As the main defect behind hypertryptophanemia is suspected to alter and disrupt the metabolic pathway from tryptophan to kynurenine, a possible correlation between hypertryptophanemia and the known effects of kynurenines on neuronal function, physiology and behavior may be of interest.One of these kynurenines, aptly named kynurenic acid, serves as a neuroprotectant through its function as an antagonist at both nicotinic and glutamate receptors (responsive to the neurotransmitters nicotine and glutamate, respectively). This action is in opposition to the agonist quinolinic acid, another kynurenine, noted for its potential as a neurotoxin.