- A relatively small (peptide) molecule that is released by the pituitary gland at the base of the brain after being made nearby (in the hypothalamus). Vasopressin has an antidiuretic action that prevents the production of dilute urine (and so is antidiuretic). A syndrome of inappropriate secretion of vasopressin which results in the inability to put out dilute urine, perturbs fluid (and electrolyte) balance, and causes nausea, vomiting, muscle cramps, confusion and convulsions may occur in association with oat-cell lung cancer, pancreatic cancer, prostate cancer, and Hodgkin's disease as well as a number of other disorders. Vasopressin has a vasopressor action and so can stimulate contraction of arteries and capillaries. Hence the name "vasopressin." Vasopressin is also known as antidiuretic hormone (ADH).
* * *A nonapeptide neurohypophysial hormone related to oxytocin and vasotocin; synthetically prepared or obtained from the posterior lobe of the pituitary of healthy domestic animals. In pharmacological doses v. causes contraction of smooth muscle, notably that of all blood vessel s; large doses may produce cerebral or coronary arterial spasm. SYN: antidiuretic hormone, Pitressin. [vaso- + L. premo, pp. pressum, to press down, + -in]- arginine v. (AVP) v. containing an arginyl residue in position 8 (as in chickens and most mammals, including humans); porcine v. has a lysyl residue at position 8. All are vasopressors. SYN: argipressin.
* * *va·so·pres·sin .vā-zō-'pres-ən n a polypeptide hormone that is secreted together with oxytocin by the posterior lobe of the pituitary gland, is also obtained synthetically, and increases blood pressure and exerts an antidiuretic effect called also antidiuretic hormone, beta-hypophamine see ARGININE VASOPRESSIN, LYSINE VASOPRESSIN, PITRESSIN
* * *n.a hormone, released by the pituitary gland, that increases the reabsorption of water by the kidney, thus preventing excessive loss of water from the body. Vasopressin also causes constriction of blood vessels. It is administered by injection to treat diabetes insipidus and to control bleeding from oesophageal varices by restricting arterial blood flow to the liver.
* * *vaso·pres·sin (va″zo-) (vas″o-presґin) 1. one of two nonapeptide hormones (the other being oxytocin) that are formed by neuronal cells of hypothalamic nuclei and stored as posterior pituitary hormones. It stimulates contraction of muscles of capillaries and arterioles, raising blood pressure; promotes contraction of the intestinal musculature, increasing peristalsis; exerts contractile influence on the uterus; and has a specific effect on the epithelial cells of renal collecting tubules, augmenting resorption of water independently of solutes to cause concentration of urine and dilution of blood serum. Its rate of secretion is regulated chiefly by the osmolarity of the plasma. 2. [USP] a synthetic pharmaceutical preparation of the same principle, used as an antidiuretic in treatment of central diabetes insipidus, administered intranasally or by injection. It is also used to induce vasoconstriction to treat hemorrhage or administered intramuscularly as a test of hypothalamo-neurohypophysial-renal function in distinguishing central from nephrogenic diabetes insipidus. Called also antidiuretic hormone.
Medical dictionary. 2011.