Expression and effect of cyclooxygenase-2 in alcoholic hepatitis in rats

Objective:To observe the expression of cyclooxygenase-2(COX-2)in alcoholic hepatitis(AH)in rats and evaluate the relationship between COX-2and AH.Methods:Twenty-four Sprague-Dawley rats were divided into four groups:normal group6rats and model group6rats were fed ethanol for four weeks,and two experimental groups(6rats in each group)were fed ethanol by the same method and after four weeks celecoxib was administered by gastric gavage.Levels of endotoxin(LPS),malonaldehyde(MDA),ALT and AST were mea-sured,and liver pathology was observed by light microscope.Expression of COX-2was studied by immunohis-tochemistry.Results:The levels of LPS and MDA in the model group increased significantly higher than those in normal group(P0.05).Serum ALT and AST levels in two experimental groups were significantly lower than those in model group(P0.05).In liver section from model group,there were markedly pathological changes(steatosis,cell infiltration and necrosis).Immunohistochemical stain showed that expression of COX-2in two ex-perimental groups decreased significantly higher than those in model group(P0.05).Conclusions:In alcoholic hepatitis the levels of LPS and MDA increase significantly and expression of COX-2occurs in association with them.The up-expression of COX-2is likely to contribute to liver injury,thus a selective COX-2inhibitor,celecoxib,might provide a protective effect on liver against ethanol-induced injury.