Human serum stimulates endothelin-1 synthesis more potently than prostacyclin production by cultured vascular endothelial cells.

Human serum stimulated the synthesis of a vasoconstrictive peptide, endothelin-1 (ET-1), and a vasodilatory prostanoid, prostacyclin (PGI2), by cultured human umbilical vein endothelial cells in a concentration- and time-dependent manner. Incubation in 20% concentration of the serum for 24 h stimulated ET-1 synthesis almost six-fold while PGI2 production increased two-fold. In addition, a tumor-promoting phorbol ester, phorbol 12-myristate 13-acetate (PMA), inhibited the serum-induced ET-1 production and stimulated PGI2 synthesis in a concentration- and time-dependent manner. Our results suggest that human serum derived factor(s) stimulate the production of vasoconstrictive ET-1 more potently than the synthesis of vasodilatory PGI2 by human vascular endothelial cells and that the production of these agents is differentially regulated by PMA.