Vasopressin inositol trisphosphate

Three subtypes of vasopressin G protein-coupled receptors have been identified. Via receptors mediate the vasoconstrictor action of vasopressin V , receptors potentiate the release of ACTH by pituitary corticotropes and V 2 receptors mediate the antidiuretic action. Via effects are mediated by activation of phospholipase C, formation of inositol trisphosphate, and increased intracellular calcium concentration. V2 effects are mediated by activation of adenylyl cyclase. 

Blackmore and Exton [5] have provided much evidence that the potentiation by glucagon of the intracellular Ca2+ mobilization induced by vasopressin is due to an enhancement of inositol trisphosphate accumulation (Fig. 11). This is probably true for its synergistic interaction with other Ca2+-mobilizing agonists. All the actions of... 

There are two major types of vasopressin receptors, VI and V2. The VI receptor occurs in vascular smooth muscle and is coupled via to activation of the phosphoinositide cascade-signaling system and generation of the second messenger inositol trisphosphate (IP3) and diacylglycerol. V2 receptors are found in kidney and are coupled via to activation of adenylate cyclase and production of the second messenger cyclic AMP. 

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