Prostaglandin Induced Inhibition of Neurotransmission in the Isolated Guinea Pig Seminal Vesicle

The contractile response of the guinea pig seminal vesicle to postganglionic nerve stimulation is inhibited by prostaglandin Ei and E2 in low doses and potentiated by high doses. Prostaglandin Ei and E2 consistently increase the contractile response to exogenous noradrenaline. The potentiation by high doses of prostaglandin Ei of the effector response to nerye stimulation is antagonized by SC 19220, inhibitor of prostaglandin action. The effect of prostaglandin Ei and E2 on the neuroeffector system of the seminal vesicle may be explained by a dual action, inhibition of noradrenaline release from the nerve terminals and potentiation of the effector response to the noradrenaline released. An endogenous prostaglandin‐mediated regulation of the smooth muscle response to nerve activity is suggested.