In males, LH stimulates which cells to produce which hormone?

• A. Leydig cells; testosterone
• B. Sertoli cells; inhibin
• C. Leydig cells; estrogen
• D. Sertoli cells; estrogen

Answer: (A)

LH from the pituitary acts on Leydig cells in the testes (the interstitial cells) to synthesize and release testosterone. This testosterone is essential for male sexual development, maintenance of secondary sexual characteristics, and (in the seminiferous tubules) support of spermatogenesis. Sertoli cells, on the other hand, respond mainly to FSH and produce factors like inhibin to regulate FSH, while estrogen is not the primary product of LH action on these cells. (Some testosterone can be converted to estrogen in peripheral tissues, but the direct effect of LH is to stimulate testosterone production by Leydig cells.)