[Expression of Smad1 and Smad5 in the testis of infertile rats with kidney-yang deficiency].

Objectives: To study the expression of Smad1 and Smad5 in the testis of infertile rats with adenine-modeled kidney-yang deficiency and the pathological mechanism of infertility with kidney-yang deficiency, attempting to obtain experimental evidence for the prevention and treatment of male infertility.

Methods: Forty-eight 60 d male SD rats were divided randomly into 6 groups with 8 in each: 7 d, 14 d and 21 d kidney-yang deficiency groups, and 7 d, 14 d and 21 d control groups. The experimental rats had been fed with adenine (300 mg/kg) and the expression levels of Smad1 and Smad5 were measured with immunohistochemical SABC method at the 7th, 14th and 21st day.

Results: Smad1 immunoreactivity was mainly located in the spermatogonia, spermatocytes and spermatids, and the reactive substance distributed in cytoplasm with negative nuclei. Sertoli cells and Leydig cells were negative. Compared with the control, the expression level of Smad1 was decreased significantly at the 21st day (P < 0.05), but with no significant difference at the 7th and 14th day (P > 0.05). Smad5 immunoreactivity was mainly located in the spermatogonia and spermatocytes, and the reactive substance distributed in cytoplasm with negative nuclei. Compared with the control, the expression level of Smad5 was not significantly different at the 7th day (P > 0.05). The expression of Smad5 was negative at the 14th and the 21st day.

Conclusion: The weaker expression of Smad1 and no expression of Smad5 may be one of the pathological mechanisms of infertility with adenine-modeled kidney-yang deficiency.