Inhibition by propranolol of high potassium-induced contractions in the rat vas deferens.

Inhibitory Action of Propranolol on the Contractions Induced by Nerve Stimulations or Calcium in the Smooth Muscle of Rat Vas Deferens

“…These results may suggest that pro pranolol inhibits Ca channels due to non specific actions on the membrane rather than the direct blocking actions of Ca channels as organic Ca-antagonists do. However, inhibition of Ca channels by propranolol may be caused by a mechanism other than one which involves local anes thetic action since inhibition of contractions by local anesthetics was much weaker in the vas deferens and coronary artery (4,21).…”

“…We previously reported that 10-5-3x10-4 M propranolol inhibited high K-induced contractions dose-dependently in the vas deferens of rats (4). The present study was undertaken to characterize the inhibitory action of propranolol in the rat vas deferens by investigating the effects on the con tractions induced by various treatments and also on the membrane potentials.…”