Abstract: 【ABSTRACT】 BACKGROUND AND AIM: To explore the effects of subchronic exposure to di-n-butyl phthalate(DBP)on testicular insulin-like factor 3 (Insl3)mRNA expression in pubertal male rats. MATERIALS AND METHODS: A total of 72 male Sprague-Dawley rats at the age of 4-5 weeks were equally randomized into 3 groups, to receive by gavage 0,50 or 250 mg/kg of DBP on alternate day for 90 days. Body, testis , epididymis and main organs were weighed. Serum testosterone, and mRNA expression of Insl3 in the testis were measured. RESULTS: There was an increase of the liver/body ratio in 250 mg/kg group after 90 days treatment(P<0.05). Compared with the control, an increase in serum testosterone was found in the 50 mg/kg group(P<0.05), but there was a reduction in 250 mg/kg group compared with the 50 mg/kg group(P<0.01)after 60 days exposure. The mRNA expressions of Insl3 were significantly down regulated in all dosage groups(P<0.01), more significantly in 250 mg/kg group than in 50 mg/kg group(P<0.05). CONCLUSION: Pubertal male rats subchronically exposed to DBP could induce changes in serum testosterone and testicular Insl3 mRNA expression,and could have potential adverse effect on the liver.

Key words: Di-n-butyl phthalate, Leydig cell, Insl3, testosterone