Abstract: AIM: To study the time-dose effects of liver damnification induced by CCl₄ in rats. METHODS: The SD rats were given sc injection 60% CCl4 twice a week to induced liver damage.After the first week, one proportion animals were killed.The contents of serum alanine aminotransferase (ALT), aspartic acid aminotransferase (ALT), hyaluronic Acid (HA), total protein (TP) and albumin (Alb) were investigated, and the thymus, liver, spleen, kidney, and the adrend gland were weighed.On the other hand, the liver tissue was studied with histopathological to observe the degrees of inflammatory activity and fibrous hyperplasia.In the coming the third, fifth, seventh, ninth week, the different proportion animals were done as the above. RESULTS: In the first week, the level of serum ALT were significantly increased;in the third week, the hepatic cells were occurred fattiness denaturalization;in the fifth week, the histopathological showed the necrotic hepatic cells obviously;in the seventh week, the histopathological displayed that the liver turned into fibrotic;and in the ninth week, the liver changed into hepaticfibrosis induced by CCl₄. CONCLUSION: The injection (sc) of 60%CCl₄ will cause diverse hepatic injury with the dissimilar durative time in rats.

Key words: toxicology, carbon tetrachloride, liver, time-dose relationship, rats