AIM:To determine the dynamic changes in the expressionof matrix metalloproteinases (MMPs) and the endogenoustissue inhibitors of MMPs inhibitors (TIMPs) during hepaticfibrosis induced by alcohol.METHODS:Male Sprague-Dawley rats were randomly dividedinto normal,4 d,2 wk,4 wk,g wk and 11 wk groups,and themodel rats were fed with a mixture of alcohol by gastricinfusion at the designed time,respectively,then decollatedand their livers were harvested for the examination of MMP-2,MMP-3,MMP-9,MMP-13,TIMP-1 and TIMP-2 by immunoh-istochemistry,zymograghy and Western blotting,respectively.RESULTS:Normal rats had moderate expression of MMP-2,which was decreased in the model rats except in the 11 wkgroup,where MMP-2 expression slightly increased.MMP-3had the similar changing pattern to MMP-2 despite weakerexpression.MMP-9 expression decreased in the 4 d and 2 wkgroups,rose in the 4 wk group,decreased again in the 9 wkgroup and returned to normal levels in the 11 wk group.MMP-13 expression decreased in the 4 d and 2 wk groups,and returned to normal levels in the 4 wk,9 wk and 11 wkgroups.TIMP-1 expression decreased in the 4 d and 2 wkgroups,but sharply increased in the 4 wk group and sustainedat a high level even after modeling was stopped for 2 wk.Innormal rats TIMP-2 expression was strong.However,itdecreased as soon as modeling began,and then graduallyrose,but remained to a level lower than that in normal ratseven after modeling was stopped for 2 wk.CONCLUSION:MMP-2 may not always expresses at a highlevel during hepatic fibrosis.MMP-13 and MMP-3 areacutely affected by TIMP-1.In this model TIMP-1 is the mostpowerful factor imposed on capillarization and peri-sinusoidalfibrosis.TIMP-2 is the most effective regulator on the metabolismof type Ⅳ collagen located in the basement of sinus. AIM: To determine the dynamic changes in the expression of matrix metalloproteinases (MMPs) and the endogenoustissue inhibitors of MMPs inhibitors (TIMPs) during hepatic fibrosis induced by alcohol. METHODS: Male Sprague-Dawley rats were randomly dividedinto normal, 4d, 2wk, 4 wk, g wk and 11 wk groups, and themodel rats were fed with a mixture of alcohol by gastric infusion at the designed time, respectively, then decollated and their livers were harvested for the examination of MMP-2, MMP-3, MMP- MMP-13, TIMP-1 and TIMP-2 by immunoh-istochemistry, zymograghy ​​and Western blotting, respectively .RESULTS: Normal rats had moderate expression of MMP-2, which was decreased in the model rats except in the 11 wkgroup, where MMP -2 expression slightly increased. MMP-3 had the similar changing pattern to MMP-2 despite weakerexpression. MMP-9 expression decreased in the 4 d and 2 wkgroups, rose in the 4 wk group, decreased again in the 9 wkgroup and returned to normal levels in the 11 wk group. MMP-13 expression decrease d in the 4 d and 2 wk groups, and returned to normal levels in the 4 wk, 9 wk and 11 w kgroups. TMP-1 expression decreased in the 4 d and 2 w kgroups, but sharply increased in the 4 wk group and the sustained a high level even after modeling was stopped for 2 weeks. Normal rats TIMP-2 expression was strong. However, it was created as soon as modeling began, and then graduallyrose, but remained to a level lower than that in normal ratseven after modeling was stopped for 2 MMP-2 may not always expresses at a high level during hepatic fibrosis. MMP-13 and MMP-3 are all affected by TIMP-1. In this model TIMP-1 is the most powerful factor imposed on capillarization and peri-sinusoidal fibrosis. TIMP-2 is the most effective regulator on the metabolism of type IV collagen located in the basement of sinus.