Effect of propranolol on endothelin-induced increase in cytosolic free calcium. This study was designed to investigate the effect of propranolol on endothelin (ET)-1-induced increase in cytosolic Ca2+ [( CA2+]i) in cultured vascular smooth muscle cells (VSMCs) obtained from rat aorta. Propranolol (0.01 to 1 mmol/L) reduced the changes in the initial transient and the later sustained phase of [Ca2+]i induced by 100 nmol/L ET-1 as well as 10 mmol/L procaine. The inhibitory action of propranolol on the change in [Ca2+]i induced by ET-1 may be involved in one of the mechanisms of propranolol-induced reduction of vasospasms. 