Vitamin A and Follicle-Stimulating Hormone Synergistically Induce Differentiation of Type A Spermatogonia in Adult Mouse Cryptorchid Testesin Vitro

Abstract

To study the mechanism of vitamin A and FSH action on testicular germ cell differentiation, artificially induced cryptorchid testes of adult mice were cultured in vitro, because such testes contain only type A spermatogonia and Sertoli cells in their seminiferous tubules. A synergistic effect of vitamin A compounds with FSH, but not with LH [luteinizing hormone], on testicular germ cell differentiation was observed. Apparently FSH stimulated the proliferation of type A spermatogonia; retinoids induce spermatogenesis from type A spermatogonia into intermediate or type B spermatogonia. Possible mechanisms of action of retinoids and FSH on testicular germ cell differentiation are discussed.