Abstract: BACKGROUND AND AIM: To study the effects on reproduction of male rats caused by the new antitumor compound, MC004. MATERIALS AND METHODS: 48 healthy and mature Wistar rats were randomly divided into 4 groups with 12 in each group. The rats of control group were given intravenous injections with normal saline and the exposure groups received MC004 at doses of 0.25，0.50 and 0.75 mg/kg. All rats were injected once in two days. All 48 rats were sacrificed after 28 days. Sperm motility was analyzed by a computer-assisted sperm analysis system and the sperm morphology was examined by microscope. RESULTS: The body weight was slowly increased and there was a significant difference between the dose of 0.75 mg/kg and the control group. Both the absolute weight and the organ weight to body weight ratios for testis and epididymis were significantly decreased(P<0.01). The epididymal cauda sperm number and the motility of the sperms were significantly decreased by MC004 treatment, while the rate of abnormal sperms was increased(P<0.01). CONCLUSION: When the male rats were treated with intravenous MC004 once in two days for 28 days, there was significant reproductive toxicity at the dose of 0.25 mg/kg.

Key words: triptolide, male rat, reproductive toxicity, sperm