Late Protective Effects of the Anticalmodulin Drug Fluphenazine on Carbon Tetrachloride-induced Liver Necrosis

Fluphenazine (FP) treatment (50mg/kg bw, ip in saline) 30 min before or 6 or 10 h after CCl4 administration (1 ml/kg ip in olive oil) significantly prevented the liver necrosis produced by the hepatotoxin at 24 h. FP had enhancing effects on the covalent binding of CCl4 reactive metabolites to cellular constituents and on CCl4 induced lipid peroaldation.FP lowered bOdy temperature of the CCl4-poisoned animals during the 24 h observation period. The obtained results are compatible but do not prove the hypothesis that calmodulin (CaM) had participation in late occurring events preceding necrosis. FP lowering action on body temperature, however, might also play a role in the effects of this drug on the onset of CCl4 induced liver necrosis. FP levels in liver tissue as determined by gas chromatography-mass spectrometry evidenced the presence of the drug in amounts suffi cient to inhibit CaM and that suggests that not all preventive effects of FP are due to its indirect actions on the central nervous system via decreased body temperature

ER Stress-Mediated Cell Damage Contributes to the Release of EDA~＋ Fibronectin from Hepatocytes in Nonalcoholic Fatty Liver Disease

Fibronectin containing extra domain A（EDA~＋ FN）,a functional glycoprotein participating in several cellular processes,correlates with chronic liver disease.Herein,we aim to investigate the expression and secretion of EDA~＋ FN from hepatocytes in nonalcoholic fatty liver disease（NAFLD） and the underlying mechanisms.Circulating levels of EDA~＋ FN were determined by ELISA in clinical samples.Western blotting and flow cytometry were performed on L02 and Hep G2 cell lines to analyze whether the levels of EDA~＋ FN were associated with endoplasmic reticulum（ER） stress-related cell death.Circulating levels of EDA~＋ FN in NAFLD patients were significantly higher than those in control subjects,and positively related with severity of ultrasonographic steatosis score.In cultured hepatocytes,palmitate up-regulated the expression of EDA~＋ FN in a dose-dependent manner.Conversely,when the cells were pretreated with 4-phenylbutyrate,a specific inhibitor of ER stress,up-regulation of EDA~＋ FN could be abrogated.Moreover,silencing CHOP by sh RNA enhanced the release of EDA~＋ FN from hepatocytes following palmitate treatment,which was involved in ER stress-related cell damage.These findings suggest that the up-regulated level of EDA~＋ FN is associated with liver damage in NAFLD,and ER stress-mediated cell damage contributes to the release of EDA~＋ FN from hepatocytes.

ENDOTOXIN-INDUCED LIVER INJURY AND CHANGES IN THE LEVELS OF PLASMA TUMOR NECROSIS FACTOR-α AND INTERLEUKIN-6 IN RABBITS

ELISA was employed to detect changes in plasma TNF-α and IL-6 level in rabbits having endotoxin-induced generalized Shwartzman reaction. Liver injury was assessed by the increase of serum ALT and hepatic histopathologic changes. The results showed that plasma TNF-α and IL-6 levels increased remarkably 12h after intravenous injection of endotoxin twice at a 24h interval, and these changes corresponded with the degree of liver injury. Coinjection of dexamethasone and endotoxin partly prevented the elevation of TNF-α and IL-6 levels and reduced liver injury. These results indicated that TNF-α and IL-6 were involved in endotoxin-induced liver injury.