PRESENCE AND SECRETION OF ATRIAL-NATRIURETIC-PEPTIDE FROM CULTURED HUMAN AORTIC ENDOTHELIAL-CELLS

The endothelium is the production site of several potent vasoactive su bstances that modulate vascular tone and growth. The present study was undertaken to investigate the presence and secretion of atrial natriu retic peptide (ANP) immunoreactivity from vascular endothelial cells. ANP immunoreactivity was present in cultured human aortic endothelial cells by both immunohistochemical staining and radioimmunoassay. ANP i mmunoreactivity was also detectable in culture medium from human aorti c endothelial cells in low picogram concentrations. These findings sug gest that vascular endothelium is a site of ANP production and secreti on of ANP. There was a differential distribution of ANP and endothelin -1 (ET-1), with a higher ANP concentration in cell extracts and a high er ET-1 concentration in cell culture media. Although ANP has been con ceived as a circulating endocrine hormone, these findings are consiste nt with ANP functioning also as an autocrine and paracrine modulator i n the regulation of vascular tone and growth.