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 var ious neuroendocrine systems. In the present study, we examined whether CNP acts directly on arginine-vasopressin (AVP) secretion from rat su praoptic nucleus (SON) neurons, using acute dissociated cell preparati ons. CNP inhibited the basal secretion of AVP in a dose-dependent mann er (10(-11)-10(-6) M). A- type natriuretic peptide (ANP) and B-type na triuretic peptide (BNP) also suppressed the basal secretion of AVP, ho wever, the effects were two-orders of magnitude less potent than CNP. CNP also suppressed AII-induced AVP secretion, however, the inhibitory effect of CNP was less than that of ANP or BNP, These findings sugges t that CNP inhibits the basal secretion of AVP through natriuretic pep tide receptor (NPR)-B and has a role in the body water and electrolyte homeostasis in the central nervous system. (C) 1997 Elsevier Science Ireland Ltd.