Адамның AVPR1B гені: Вазопрессин V1b рецепторы және оның функциялары

Protein coding gene in the species Homo sapiens

Vasopressin V1b receptor (V1BR) also known as vasopressin 3 receptor (VPR3) or antidiuretic hormone receptor 1B is a protein that in humans is encoded by the AVPR1B (arginine vasopressin receptor 1B) gene. V1BR acts as a receptor for vasopressin. AVPR1B belongs to the subfamily of G protein coupled receptors. Its activity is mediated by G proteins which stimulate a phosphatidylinositol calcium second messenger system. It is a major contributor to homeostasis and the control of water, glucose, and salts in the blood. Arginine vasopressin has four receptors, each of which are located in different tissues and have specific functions. AVPR1b is a G protein coupled pituitary receptor that has only recently been characterized because of its rarity. It has been found that the 420 amino acid sequence of the AVPR1B receptor shared the most overall similarities with the AVP1A, AVP2 and oxytocin receptors. AVPR1B maps to chromosome region 1q32 and is a member of the vasopressin/oxytocin family subfamily.

AVPR1B was initially described as a novel vasopressin receptor located in the anterior pituitary, where it stimulates ACTH release. Subsequent studies have shown that it is also present in the brain and some peripheral tissues.

Inactivation of the Avpr1b gene in mice (knockout) produces mice with greatly reduced aggression and a reduced ability to recognize recently investigated mice. Defensive behaviour and predatory behaviours appear normal in these knockout mice, but there is evidence that social motivation or awareness is reduced. The AVPR1B antagonist, SSR149415, has been shown to have anti aggressive actions in hamsters and anti depressant and anxiety (anxiolytic) like behaviors in rats. A single nucleotide polymorphism (SNP) has been associated with susceptibility to depression in humans.

AVPR1B is expressed at high levels in ACTH secreting pituitary adenomas as well as in bronchial carcinoids responsible for the ectopic ACTH syndrome.

Nelivaptan (SSR149415) and D [Leu4 Lys8] vasopressin are a specific antagonist and agonist for the vasopressin 1b receptor, respectively.

AVPR1B is found in different parts of the body and thus has several influences and regulatory actions. Arginine vasopressin influences several symptoms related to affective disorders including significant memory processes, pain sensitivity, synchronization of biological rhythms and the timing and quality of REM sleep. AVPR1b has also shown involvement in regulation of brain water content and cerebral edema. This was revealed as increased levels of AVPR1B mRNA on the choroid plexus were discovered as a result of increased plasma osmolality. The increase after a reduction of brain water content from salt water loading indicated AVPR1B's role in the neuroendocrine feedback loop in maintaining normal central nervous system fluid balance.