Reproductive defects in the male diabetic athymic nude mouse

We have previously reported spontaneous hyperglycemia and impaired glucose tolerance in male athymic nude Balb/c mice. This colony also demonstrates impaired fertility. Previous studies in both athymic nude and diabetic obese (ob/ob) mice have shown reproductive abnormalities. It was the purpose of this investigation to further elucidate the endocrine abnormalities which might contribute to the reduced fertility observed in this model. Fasting plasma glucose was measured on each nude mouse to ensure that a diabetic state existed. Testes were removed and intratesticular testosterone and LH receptors were measured. Testosterone levels in diabetic, athymic nude Balb/c (DAN) mice were significantly decreased to 46.5% of control Balb/c mice. LH receptors in DAN mice were significantly elevated by 23.6% when compared to control animals. These results demonstrate that the impaired fertility observed in the DAN mouse may result from decreased testosterone production. The increased LH receptor levels seen in the DAN mouse might reflect a regulatory event in response to the decreased intratesticular testosterone levels.