Mitochondrial- and Fas-L-mediated pathways involved in quinestrol induced spermatogenic apoptosis in adult rat testes.

The pathways involved in quinestrol-induced spermatogenic apoptosis were studied in adult male rat by using daily intragastric administration of 0.01 mg/kg, 0.1 mg/kg and 1 mg/kg body weight quinestrol for two consecutive weeks. The immunohistochemistry staining was performed to measure the expression of proliferating cell nuclear antigen (PCNA), caspase-3, Bax, Bcl-2, Fas and FasL. The results showed that testes weights and the size of seminiferous tubule (ST) decreased as well as the organization of the ST changed significantly after treatment with 1 mg/kg quinestrol. The number of germ cells expressing caspase-3, Bax, Fas and FasL markedly increased whereas the numbers of cells expressing Bcl-2 and PCNA significantly decreased in the group treated with quinestrol at 1 mg/kg compared with the control. The results suggest that quinestrol induced abnormal spermatogenesis through the mitochondrial- and Fas-L-mediated pathways after quinestrol exposure in male rat.