C-type natriuretic peptide suppresses arginine-vasopressin secretion from dissociated magnocellular neurons in newborn rat supraoptic nucleus.

Central administration of C-type natriuretic peptide (CNP) affects various neuroendocrine systems. In the present study, we examined whether CNP acts directly on arginine-vasopressin (AVP) secretion from rat supraoptic nucleus (SON) neurons, using acute dissociated cell preparations. CNP inhibited the basal secretion of AVP in a dose-dependent manner (10(-11)-10(-6) M). A- type natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) also suppressed the basal secretion of AVP, however, the effects were two-orders of magnitude less potent than CNP. CNP also suppressed All-induced AVP secretion, however, the inhibitory effect of CNP was less than that of ANP or BNP. These findings suggest that CNP inhibits the basal secretion of AVP through natriuretic peptide receptor (NPR)-B and has a role in the body water and electrolyte homeostasis in the central nervous system.