RESUMO
Objective To investigate the protective effect of melatonin on renal injury induced by bile duct ligation in rats. Methods Sixty four rats were randomly divided into four experimental groups ( n =16 rats per group): the control group (CN), sham operative group (SO), bile duct ligation group (BDL) and bile duct ligation melatonin treatment group (BDL+Mel). Obstructive jaundice was induced by common bile duct ligation. Plasma level of nitric oxide (NO), total bilirubin (TB), direct bilirubin (DB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea nitrogen (BUN) and creatinine (Cr) were measured 4 d and 8 d after operation. NO and inducible nitric oxide synthase (iNOS) in renal tissue were detected at the same time point, too. Histopathological changes of kidneys were examined by HE staining. Results In BDL group, the plasma levels of NO, TB, DB, ALT, AST, BUN and Cr were higher than those of SO group ( P