Initiation of Spermatogenesis in Vitro1

The in vitro effect of gonadotropins (FSH, HCG) and vitamins (A, E, C) on spermatogenesis was studied in organ cultures of 4-day-old rat testes. The techniques employed permitted long-term maintenance of basic tissue structure and survival of primitive germ and supporting cells. Addition of NIH-FSH-S-1 to the culture medium, in concentrations of 20, 50 or 100 μg/ml, resulted in changes of supporting cells compatible with maturation; however, formation of more mature germinal cells from primitive type A spermatogonia was not induced. Similar changes were produced by HCG (Follutein, Squibb) in a concentration of 100 μ/ml. Lower doses (20 or 50 μ/ml) had no effect. Differentiation of the germinal epithelium up to the stage of primary spermatocytes proceeded when the culture medium contained vitamins A (12 μ/ml), C (50 μg/ml) and E (120 Mg/ml). These data indicate that spermatogenesis can progress in vitro from the primitive germinal cell to the stage of primary spermatocytes in the absence of gonadotropins, providing vitamins A, E and C are present in the culture medium. (Endocrinology74: 788, 1964)