Table 1. Subtype, Second Messenger, Localization, and Function of Vasopressin Receptor.

Subtype	Signaling pathway	Location	Function
V1	G protein-coupled, phosphatidylinositol/calcium	Vascular smooth muscle	Vasoconstriction
		Platelet	Platelet aggregation
		Liver	Glycogenolysis
		Myometrium	Uterine contraction
		Kidney	Efferent arteriolar constriction
		Brain	Temperature regulation
			Cognitive function (learning and memory)
			Emotional response (anxiogenic and depressive actions, stress adaptation)
			Social behavior (pair-bonding behavior, aggressive and affiliative behavior)
V2	G protein-coupled, adenylate cyclase/cAMP	Kidney collecting duct cells	Insertion of aquaporin-2 channels
		Vascular endothelium	Release of vWF and factor VIII
V3	G protein-coupled, phosphatidylinositol/calcium	Anterior pituitary lobe	Corticotropin, growth hormone, and prolactin secretion
		Brain	Stress adaptation, cognitive function, regulation of social behavior

cAMP: cyclic adenosine monophosphate, vWF: von Willebrand factor.