Experimental cryptorchidism in the adult mouse: II. A hormonal study

Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone levels and secretory capacity of the in vitro stimulated testis were determined in control and bilateral cryptorchid mice after 7, 14, 21, and 28 days. In a separate study, serum FSH, LH, and testosterone levels were measured in unilateral and bilateral cryptorchid, hemicastrate, and bilaterally castrate adult mice after 28 days of treatment. Serum FSH levels were significantly increased in bilaterally cryptorchid mice compared to controls (0 days) at 7, 14, 21, and 28 days, but serum LH and testosterone levels did not change. At 28 days, the elevated serum FSH levels in the unilateral and bilateral cryptorchid mice were not different than those in hemicastrate mice. However, the FSH levels in bilaterally castrate mice after 28 days were significantly higher than all other groups. Serum LH and testosterone levels were significantly different only in the bilaterally castrate group, compared to control levels. Both the normal and cryptorchid testes of all ages studied were capable of producing equal levels of testosterone in vitro, both basally and with a human chorionic gonadotropin (hCG) dose of 700 mIU/ml (maximum stimulatory dose for both the normal and the 28 day cryptorchid testes). Changes that occur in mice with experimentally induced cryptorchidism are not identical to those seen in the rat. Serum FSH levels increase, but no changes occur in serum LH and testosterone levels. Additionally, a cryptorchid mouse testis is not hyperresponsive to hCG stimulation in vitro.