Vasodilator effects of C-type natriuretic peptide on cerebral arterioles in rats.

The vasodilator effects of C-type natriuretic peptide (CNP) were investigated in isolated rat cerebral arterioles. CNP caused dose-dependent vasodilation, maximally by 10.0 +/- 2.2% at 10(-6) M. The median effective concentration (EC50) was 5.2 x 10(-10) M. In contrast, atrial natriuretic peptide and B-type natriuretic peptide, other members of the natriuretic peptide family, produced little or no vasodilation. Pretreatment with methylene blue (10(-4) M) abolished CNP-induced vasodilation, whereas pretreatment with NG-monomethyl-L-arginine or indomethacin did not inhibit vasodilation. Thus, CNP is suggested to cause significant vasodilation in cerebral arterioles via a cyclic guanosine monophosphate-dependent mechanism.