Response of Rabbit Testicular Capsular Contractions to Testosterone,Prostaglandin E 1,and Isoproterenol in Vitro and in Vivo 1

Abstract

Summary

Rabbit testicular capsular contractions in vitro were inhibited by 5α-androstan-17β-01-3-one, androstenedione, 17α-hydroxyprogesterone, and testosterone with approximately the same potency. Testosterone did not inhibit spontaneous contractions in vivo, but it did partially inhibit PGE₁ potentiated contractions in vivo. Capsular preparations responded similarly to PGE₁ and isoproterenol both in vitro and in vivo indicating that it was not the route of administration that determined the response of the capsule to testosterone. By contrast, spontaneous contractions in vivo could not be abolished by repeated changes of the bathing media as previously reported for in vitro preparations. These data negate the possible regulation of testicular contractions by endogenous steroids.

We thank Dr. John E. Pike of the Upjohn Co. for the prostaglandins used in this study.