Effects of acetylcholine and some other smooth muscle stimulants on the electrical and mechanical responses of the guinea-pig vas deferens to nerve stimulation.

Abstract

AbstractSjöstrand, N. O. Effects of acetylcholine and some other smooth muscle stimulants on the electrical and mechanical responses of the guinea‐pig vas deferens to nerve stimulation. Acta physiol. scand. 1973. 89. 1–9.The effect of acetylcholine (Ach), histamine, 5‐hydroxytryptamine, Ba2+ and bradykinin on the electrical and mechanical responses of the guinea‐pig vas deferens to nerve stimulation was investigated with the sucrose gap technique. The agonists produced a depolarization of the smooth muscle membrane. Because of this the membrane came closer to the threshold for firing of action potentials (AP:s). The AP:s also increased in size in the presence of the agonists and the contractions became larger. Atropine abolished the effect of Ach. The results indicate that the agonists enhance the motor response of the vas deferens by a direct action on the smooth muscle cell membrane.