Culture and FSH Responses of Sertoli Cells Isolated from Sexually Mature Rat Testis

Abstract

We have previously provided evidence that ¹²⁵I-FSH specifically binds to various preparations of rat testis which contain Sertoli cells, e.g. isolated seminiferous tubules and organ cultures of testicular explants which have been depleted of most germinal elements and Leydig cells (1,2). On the other hand, isolated germinal cells, peritubular cells or interstitial cells show no binding of the labeled FSH. Subsequently, it was demonstrated that FSH also stimulates endogenous cAMP (3′5′-cyclic adenosine monophosphate) levels in the isolated seminiferous tubules and organ cultures, but has no effect on the isolated peritubular or interstitial cells and only a slight stimulatory effect on the germinal cells (3). These results provided suggestive evidence that of the various cell types composing the testis, only the Sertoli cells possess the FSH binding receptors and respond to FSH stimulation with increased levels of cAMP. Since these two parameters are considered to be the initial steps of gonadotropin action in the target cells (4), it appeared that the Sertoli cells must represent the primary target site for the biological action of FSH in the testis.