<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>Specific molecular sites or structures on or in cells that vasopressins react or to which they bind in order to modify the function of the cells. Two types of vasopressin receptor exist, the V1 receptor and the V2 receptor. The V1 receptor can be subdivided into V1a and V1b (formerly V3) receptors.</n0:def-definition><n0:def-source>MSH2001</n0:def-source></n0:ComplexDefinition>
<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>Neurohypophyseal vasopressin is a cyclic nonapeptide involved in diverse actions, including the control of body fluid osmolality, blood volume, blood pressure, vascular tone, hepatic glycogenolysis, vascular smooth muscle and mesangial cell contraction, nephric antidiuresis, and platelet aggregation. Vasopressin binds to three GPCR subtypes: V1A, V1B, and V2. The V1A receptor is located in liver, vascular smooth muscle, brain, mesangial cells, and platelets. It mediates cell contraction and proliferation, platelet aggregation, release of coagulation factor, and glycogenolysis. V1A and V1B activate PLC via Gq/11, which increases intracellular calcium. Arginine VP modulates ACTH, beta-endorphin, and prolactin release, mediated by V1B. V2 is expressed exclusively in the kidney and mediates the antidiuretic effect of arginine VP by activating adenylyl cyclase via interaction with Gs. (from OMIM 600821, 600264, and NCI)</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition><n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>The biologic effects of arginine vasopressin (AVP) are mediated by 3 receptor subtypes: the V1A and V1B receptors that activate phospholipases via Gq/11, and the V2 receptor that activates adenylyl cyclase by interacting with GS. This subfamily of G-protein coupled receptors also includes OXT receptors. Their activity is mediated by G proteins which stimulate a phosphatidylinositol-calcium second messenger system. All are involved in the control of body fluid osmolality, blood volume, blood pressure, and vascular tone. (from OMIM)</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>