Contractility of rat testicular seminiferous tubules in vitro: prostaglandin f 1 alpha and indomethacin-1,2.

The frequency of spontaneous in vitro contractions of seminiferous tubules of the rat appeared to be increased in a dose-dependent manner by prostaglandin F1alpha. PGF1alpha treatment increased the tonus of the smooth muscle cells in the wall of the tubules as indicated by a reduction in the diameter of the tubules. When the tubules were rinsed successively with fresh Tyrode's solution, the contractile frequency was diminished. Returning the original bathing medium to the tubules restored their contractile frequency, as did treatment of the rinsed tubules with PGF1alpha (10(-7) M). Preinjecting ther rats with indomethacin tended to reduce the contractile frequency of the extirpated tubules. Treating the tubules with a solution of indomethacin for 90 min. in vitro was more effective than pretreatment in vivo in reducing contractile frequency, but a combination of these two procedures produced the greatest inhibition. PGF1alpha restored the contractile frequency of the indomethacin-treated tubules. Our results indicate that PGs modulate the in vitro contractility of the tubules.