Action of Anterior Pituitary on Sertoli Cells and on Release of Toad Spermatozoa

Abstract

Houssay and Lascano Gonzalez 1 found that in the testis of toads, in which anterior pituitary glands were implanted, spermatozoa were released into the lumen of the seminiferous tubules. Rugh 2 , 3 confirmed this observation finding that the infection of pituitary extract produces, in the testis of hibernating frog, the release of the spermatozoa, normally attached to the Sertoli cells. The author gives no explanation of the mechanism by which the spermatozoa are released into the lumen, but suggests that: “Possibly smooth muscle fibers are involved in the expulsion of spermatozoa from the tubules” (Rugh 3 ).

In order to investigate the actual mechanism of this release, toads (Bufo arenarum Hensel) in sexual rest (end of summer) were injected intravenously with a total extract of 3 anterior lobes of the pituitary gland of male toads.

Thirty minutes, one, 2,3, and 5 hours after the injection, the testes were fixed in Bouin or in Zenker-formol fluids; and also in the fixative of Champy, followed for 7 days by immersion in osmic acid at 38°C. Testes of normal control animals showed almost all mature spermatozoa clustered about their Sertoli cells (Fig. 1). Thirty minutes after the injection of the pituitary extract some of the spermatozoa have been liberated. The Sertoli cells showed big increase and vacuolization of cytoplasm (Fig. 2). After one hour, clear hydropic vacuoles were more conspicuous and also some acidophil droplets were found (Fig. 3). The vacuoles have the tendency to aggregate and seem to push the spermatozoa away from the tubule wall. Three hours after the injection almost all mature spermatozoa have been released. Most of the Sertoli cells appear enormously vacuolized and with the apical border completely irregular, due to the rupture of some vacuoles (Fig. 4).