Androgen Effects on Rat Leydig Cells

Treatment of hypophysectomized, 30-day-old male rats with 5 mg dihydrotestosterone propionate (DHTP) or testosterone propionate (TP) daily for 5–6 days resulted in a marked reduction in the magnitude of the maximum steroidogenic response of Leydig cells to hCG. This effect was not mediated through alterations in the LH receptor binding to testicular particles and did not represent a direct competitive inhibition of the steroidogenic enzymes.The possible involvement of androgens in a ultra-short loop negative feedback on steroidogenesis is discussed in relation to the phenomenon of Leydig cell desensitization.