Secretion of Brain Natriuretic Peptide in Cultured Human Coronary Vascular Smooth Muscle Cells

Abstract Brain natriuretic peptide (BNP) is a peptide of cardiac origin which regulates plasma volume as well as vascular tone and growth. Recently, we have reported that brain natriuretic peptide is a potent inhibitor of endothelin-1-mediated proliferation in human coronary vascular smooth muscle cells (HCoVSMC). While brain natriuretic peptide has been reported to be produced and released from atrial and ventricular myocardium, we hypothesize that brain natriuretic peptide may be present and secreted from human coronary vascular smooth muscle cells. Therefore, the present study was designed to investigate the secretion of brain natriuretic peptide in cultured human coronary vascular smooth muscle cells (HCoVSMC: Clonetics, San Diego, CA). The concentration of brain natriuretic peptide, and its second messenger cGMP, in culture media (48 hours) was determined by radioimmunoassay (Phoenix, Mountain View, CA). The presence of brain natriuretic peptide was determined by immunohistochemical staining using a human brain natriuretic peptide polyclonal antibody.