OBJECTIVETo observe the protective effects of vitamin E on the testicular injury by cyclophosphamide in mice, and the correlative mechanism.

METHODSFifty sexually mature male mice were randomly divided into five groups: the cyclophosphamide group (the CP group), the low-dose vitamin E group (the low-dose group), the middle-dose vitamin E group (the middle-dose group), the high-dose vitamin E group (the high-dose group), the matched control group (the control group). The first four groups were given cyclophosphamide by gavage at a dose of 5 mg/(kg x d). The low-dose group, the middle-dose group and the high-dose group were given vitamin E by subcutaneous injection at doses of 30 mg/(kg x d), 50 mg/(kg x d) , 70 mg/(kg x d) after 4 h of cyclophosphamide treatment. The control group was gavaged with equivalent normal saline. The treatment period for all groups was 28 days. The level of plasma FSH, LH, T and the activity of testicular SOD, GSHPx, CAT and the level of testicular MDA were detected. The histological structure and the ultrastructure of the testis were examined by light microscope and electron microscope.

RESULTSAs compared with the CP group, the plasma FSH, LH, T level and the SOD, GSHPx, CAT activity in the middle-dose group and the high-dose group were higher (P< 0.05, P< 0.01), MDA level significantly lower(P<0.01). The histological structure and the ultrastructure of the testis were in the normal range.

CONCLUSIONVitamin E has protective effects on the testicular injury by cyclophosphamide in mice. The possible mechanism of vitamin E may be its scavenging free radical and antioxidant effects, as well as it may have some stimulatory effects on gonadotrophin releasing of pituitary anterior lobe.