Abstract: BACKGROUND AND AIM: To study the effects of polychlorinated biphenyl(PCB) on rat liver structure and function. MATERIALS AND METHODS: 40 male Wistar rats were divided into four groups , A group was control group , B group (fed with 10－8 mol/L PCB)， C group(10－7 mol/L PCB), D group(10－6 mol/L PCB) as experimental groups.After three months, all rats were killed . Immunohistochemical and biochemical methods were used to observe the effects of PCB on liver structure and function in rats. RESULTS: The strutural damage of the liver was related to the dose of PCB, with D group showing more severe damage than that of others. PCB could induce c-fos expression in the liver, which was higher in C and D groups compared with other groups (P<0.05). PCB could promote the expression of bcl-2 in liver,with higher expression in C and D groups than that of A and B groups. PCB also could affect biochemical function of liver, such as URIC,TBLL,DBLL,AST,ALT,TP3,LDH to increase in C and D groups compared with A and B groups. CONCLUSION: PCB could lead to liver injuries in the rats.

Key words: polychlorinated biphenyl, liver, c-fos, bcl-2