【Abstract】ObjectiveTo investigate the protective effect of melatonin on renal injury induced by bile duct ligation in rats. MethodsSixtyfour 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. ResultsIn BDL group, the plasma levels of NO, TB, DB, ALT, AST, BUN and Cr were higher than those of SO group (P＜0.01）, and the level of NO and activities of iNOS in renal tissue were significantly increased (P＜0.01）. However, in BDL+Mel group, the plasma levels of NO, ALT, AST, BUN and Cr were lower than those of the BDL group (P＜0.01）, and the level of NO and activities of iNOS in renal tissue were significantly suppressed (P＜0.01）; histopathological changes of kidneys were improved.ConclusionAugmentation of iNOS activities and increasing of NO production in local tissue contributed to renal injury induced by bile duct ligation, and the mode of melatonin’s protective actions, at least in part, relates to interference with no pathways.
Objective To investigate the protective effect of melatonin on rat liver injury induced by bile duct ligation. Methods Sixty-four rats were randomly divided into four groups：control group （CN group， n=16）， shamoperation group （SO group， n=16）， bile duct ligation group （BDL group， n=16）， and bile duct ligation with melatonin injection （BDL＋MT group， n=16）. The model of obstructive jaundice was done by ligation of the common bile duct. Melatonin was injected daily （0.5 mg/kg） via peritoneal cavity from 1 d before the operation to 7 d following oper-ation. On day 4 and 8 after the ligation， the plasma levels of total bilirubin （TBIL）， alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， gamma glutamyl transferase （GGT）， and alkaline phosphatase （AKP） were measured by routine methods. Malonaldehyde （MDA）， superoxide dismutase （SOD）， glutathione （GSH）， catalase （CAT）， and glutathione peroxidase （GSH-Px） in the liver tissue were determined by spectrophtometry， too. Hepatocytes apoptosis was analyzed by terminal deoxynucleotidyl transferase-mediated deoxynuridine triphosphate nick-end labeling （TUNEL） assay. Results Compared with the CN group and SO group， the levels of TBIL， ALT， AST， GGT， and AKP in the plasma， the content of MDA in the liver tissue， and the apoptosis index （AI） in the hepatocyte markedly increased （P＜0.05， P＜0.01）， the content of GSH and the activities of SOD， CAT， and GSH-Px in the liver tissue markedly decreased（P＜0.01） in the BDL group. Compared with the BDL group， the levels of TBIL， ALT， AST， GGT， and AKP in the plasma， the content of MDA in the liver tissue， and the AI in the hepatocyte markedly decreased （P＜0.01）， the content of GSH and the activities of SOD， CAT， and GSH-Px in the liver tissue markedly increased （P＜0.01） in the BDL＋MT group. In the BDL group， the level of MDA in the liver tissue and the levels of TBIL， ALT， AST， GGT， and AKP were positively correlated （P＜0.01）， the content of GSH and the activities of SOD， CAT， and GSH-Px in the liver tissue and TBIL， ALT， AST， GGT， and AKP were negatively correlated （P＜0.01）. The level of MDA in the liver tissue and AI in the hepatocyte was positively correlated （P＜0.01）. The content of GSH and the activities of SOD， CAT， and GSH-Px in the liver tissue and AI were negatively correlated （P＜0.01）. Conclusions The participation of free radical of oxygen in the pathogenesis and severity of cholestasis produced by the acute obstruction of the extra-hepatic biliary duct is likely. The result of the present study indicates that melatonin exerts a protective effect on cholestatic liver injury in rats with BDL. The mechanism of melatonin’s protection on hepatocyte may be through its antioxidant action and by inhibiting hepatocyte apoptosis.
ObjectiveTo study the value of Gd-DTPA three dimension fast spoiled gradientecho (3D FSPGR) dynamic MRI in the diagnosis and preoperative respectability assessment of pancreatic carcinoma.MethodsThirty-two cases of pancreatic carcinoma verified by surgery and pathology were included in this study. All of the cases had MRI examinations two weeks before surgery. MRI protocols involved gradient echo T1 weighted（GRE T1W） with fat suppression, fast spin echo respiratory gating T2 weighted (FSE RG T2W) with fat suppression, MR cholangiopancreatography (MRCP) and gadolinium chelate 3D FSPGR T1W dynamic enhancement. Two radiologists reviewed MRI of the 32 cases retrospectively. Preoperative resectability of pancreatic carcinoma was assessed according to the characteristics of tumor lesions, peripancreatic invasion, vascular invasion, lymph node metastases, and liver metastases. The diagnosis and preoperative resectability assessment of pancreatic carcinoma by MRI was compared with surgical findings. ResultsOf 32 cases, 29 cases diagnosed by MRI were confirmed by surgery and pathology (accuracy of MRI, 90.6%). The sensitivity was 84.4%(27/32) and 93.8%(30/32) respectively for GRE T1W with fat-suppression combining FSE RG T2W and for Gd-DTPA 3D FSPGR dynamic MRI in the detection of pancreatic tumors. The accuracy was 87.5%（21/24）, 87.0%（20/23）, 80.0%（12/15）, 88.9%（8/9） and 83.3%（5/6） respectively for Gd-DTPA 3D FSPGR dynamic MRI in assessing local extension, vascular invasion, lymph node metastases, liver metastases and peritoneal carcinomatosis of pancreatic carcinoma. Eight cases of pancreatic carcinoma were considered to be resectable by enhanced MRI, while the tumors in 7 cases of the 8 cases were resected by surgery. Twentythree cases were confirmed nonresectable by surgery in the 24 cases of pancreatic carcinoma considered to be non-resectable by enhanced MRI. The sensitivity, specificity and accuracy were 87.5%，95.8% and 93.8% resectability for the assessment of respectability of pancreatic carcinoma by using Gd-DTPA 3D FSPGR dynamic MRI. There was no significant difference in the assessment of the resectability of pancreatic carcinoma between enhanced MRI and surgery or pathology （κ=0.83）.ConclusionUsing of Gd-DTPA 3D FSPGR dynamic enhanced MRI improves the detections of pancreatic carcinoma and metastasis. It is also accurate in the assessment of the resectability of pancreatic carcinoma.