[Interaction between gonadotropins and "Transforming Growth Factor Beta" (TGF Beta) in testicular function control]

Testicular function is regulated not only by circulating hormones, among which the gonadotrophins play the main role, but also by local factors originating in multiple and complex interactions among cells. In this review, the example of gonadotrophins (LH and FSH) and Transforming Growth Factor beta (TGF beta) was chosen to illustrate the role of interactions between circulating hormones and gonadal growth factors in testicular function control; TGF beta-like activity has been found in the male gonad and we have used a model of cultured purified testicular cells to show that the action of TGF beta on testicular function mainly involves antagonism of the effect of gonadotrophins. Conversely, TGF beta promotes differentiated Leydig and Sertoli cell function. The example of interactions between TGF beta and gonadotrophins reported here shows that locally produced growth factors can regulate the response of testicular cells to gonadotrophins, a finding that extends our concept of reproductive endocrinology to cell-cell interactions.