Endothelin stimulates a sustained 1,2-diacylglycerol increase and protein kinase C activation in bovine aortic smooth muscle cells.

Endothelin is a long-lasting potent vasoconstrictor peptide. We report here that in bovine aortic smooth muscle cells, endothelin biphasically increased total cellular diacylglycerol (DAG) content. When cellular DAG was labeled with [14C] glycerol for 48h, endothelin stimulated [14C]DAG formation in a biphasic pattern. Only one prolonged phase of DAG accumulation was observed when cells were labeled with [3H]glycerol for 2 h. Endothelin induced an increase in the membranous protein kinase C (PKC) activities, which lasted for more than 20 min. These data suggest that (i) endothelin stimulates a sustained generation of DAG, (ii) this accumulation of DAG results in a sustained translocation of cytosolic PKC activities to the membrane.