Does endothelin mobilize calcium from intracellular store sites in rat aortic vascular smooth muscle cells in primary culture?

In the presence of endothelin, there was a rapid increase in the 45Ca ++ efflux from primary cultured rat vascular smooth muscle cells, both in physiological salt solution and in calcium free medium containing 2 mM EGTA. The 45Ca ++ influx was not affected. The endothelin-induced, transient increase in cytosolic calcium concentration is probably mainly due to release of calcium from the intracellular store in vascular smooth muscle cells.