Effects of prostaglandins and indomethacin on rat epididymal responses to norepinephrine and acetylcholine.

Prostaglandins E2 and F2alpha tromethamine salt caused an increase in amplitude and frequency of rat epididymal contractions. Moreover, they caused a significant potentiation of contractile responses of epididymal smooth muscle to stimulation by norepinephrine or acetylcholine. Indomethacin treatment caused no changes in the spontaneous motility, and this inhibitor of prostaglandins synthesis decreased the responses of epididymis to norepinephrine or acetylcholine. Spontaneous motility of epididymis is possible in the presence of smaller amounts of endogenous prostaglandins, and sudden contraction occurring during ejaculation, induced by sympathetic and parasympathetic nerves stimulation, could be influenced or modulated by prostaglandins.