Abstract: This experiment was aimed to study the effect of quinestrol on the expression of PCNA and Caspase-3 in spermatogenic cells of juvenile mice. 4-week old male mice were randomly divided into four groups. Mice in the control group were injected intraperitoneally with olive oil alone and mice in the experiment groups were injected intraperitoneally with octylphenol resolved in olive oil at 1, 10, 100 mg/kg doses respectively for 1 week (once a day). The testes were immediately removed for weighing and serial cross-sections that were used for histological examination when the mice were 8-week-old. The expressions of PCNA and Caspase-3 in spermatogenic cells were determined by immunohistochemical method. The results showed that the thickness of the convoluted seminiferous tubule decreased, cellular deranged, cell layers decreased and intercellular space increased. Meanwhile, there were a large number of abnormal shedding of spermatocytes and round spermatids, but few elongated spermatids and spermatozoa. The expression of PCNA extremely significantly decreased and the expression of Caspase-3 extremely significantly increased as quinestrol dose increased (P＜0.01). Quinestrol caused male reproductive function injury through inhibiting proliferation and promoting apoptosis in spermatogenic cells by regulating the expression of associated proteins.

Key words: spermatogenic cell; quinestrol; proliferation; apoptosis