C-type natriuretic peptide is a growth inhibitor of rat vascular smooth muscle cells.

Abstract C-type natriuretic peptide (CNP) which potently stimulates particulate guanylate cyclase activity in cultured rat vascular smooth muscle cells (VSMC) inhibited serum-induced DNA synthesis of the cells 10-fold more effectively than α-human atrial natriuretic peptide (α-hANP). The inhibitory effect of CNP was mimicked by 8-bromo-cGMP. The proliferation of VSMC was also suppressed by CNP more potently than α-hANP, while the peptide was less active for cGMP augmentation and for vasorelaxation than α-hANP in isolated rat aorta. These results suggest that CNP may be a growth regulating factor of VSMC rather than a vasodilator.