CENTRAL ACTION OF C-TYPE NATRIURETIC PEPTIDE ON VASOPRESSIN SECRETIONIN CONSCIOUS RATS

The effect of intracerebroventricular injection of C-type natriuretic peptide (CNP) on arginine vasopressin (AVP) secretion was studied in c onscious rats, and was compared to that of atrial natriuretic peptide (ANP). The AVP secretion induced by central injection of 0.1 nmol angi otensin II was significantly suppressed by the pretreatment with 1 nmo l CNP. ANP at a dose of 0.1 nmol elicited almost equivalent suppressiv e action to 1 nmol CNP. Considering that CNP is a specific ligand for ANP-B receptor, while ANP is that for ANP-A receptor, the result demon strates that CNP possesses the similar central action to ANP, and sugg ests that the distribution of ANP-A and ANP-B receptors and/or their a ffinity towards each natriuretic peptide are different in the central nervous system.