[Effect of human chorionic gonadotropin on the endocrine function of Papio testes]

Radioimmunoassay was used to study secretion of Papio hamadryas testis under stimulation with human chorionic gonadotropin (hCG). It was discovered that hCG had an acute stimulating effect on testicular secretion of testosterone, androstendione and 17-hydroxyprogesterone. It was demonstrated that repeated stimulation with hCG in the presence of the maximal secretory response of the testis (24 h after the first injection and in the presence of its partial reduction (after 72 h) did not provoke any additional rise of testosterone secretion. Unlike the initial response, repeated stimulation with hCG gave rise to dissociation in the time-course of testosterone and 17-hydroxyprogesterone responses. The data obtained attest to temporary "desensitization" of the testis to repeated stimulation with hCG.