Participation of protein kinase C in endothelin‐1‐induced contraction in rat aorta: studies with a new tool, calphostin C

1. Calphostin C at 10(-6) M was shown to be selective and highly effective in inhibiting contractile responses of rat aortae to 12-o-tetradecanoylphorbol-13-acetate, while it had no effect on contractile responses to elevated KCl. 2. In the rat aorta, endothelin-1 (ET-1) developed a sustained tonic contraction dose-dependently in both normal Ca(2+)-containing Krebs and Ca(2+)-free Krebs containing 1 mM EGTA. Calphostin C (10(-6) M), a selective …