The Mechanism Of Endotoxin Induce Non-Alcoholic Steatohepatitis

Aim:Feed the rats with high-sucrose and high-fat diet,observe the rats have fatty liver disease and IETM,then research the effect that simple LPSeffect on liverMethods:The experiment (Exp) 1. Twenty-four rats were randomly separated into two groups. The first group of eight rats were the control group which were fed three months.The second group have16 rats,they were the model group which were fed with high-sucrose and high-fat diet; At the end of the third month, Fasting the rats of model group(randomly choosing eight rats) one day, anaesthetizing with 1%pentobarbital sodium(20mg/kg), collecting Abdominal aortic blood, Centrifugating with 3500r/min for using, Collecting the left lobe hepatic tissue and the intestinal tissue that 1 cm from the ileocecal junction, and puting them in neutral formalin of 10%.Then paraffin imbedding, histological section,and hematoxylin- eosin(HE) staining respectively. Enclosed the left tissues of liver and intestine with aluminium foil paper,and put them in the refrigerator of -70℃after liquid nitrogen freezing.To deal the control group and the left rats of model group in the same methods at the end of the sixth month.Exp 2. Twenty-four rats were randomly divided into four groups.The first group of rats were the control group which were fed four weeks.The second were injected endotoxin for four weeks(LPS group).The third were also regarded as control group which were fed for nine weeks.The forth group were injected endotoxin for nine weeks. subcutaneous injection endotoxin(40ug/100g weight) once every other day, All of rats were fed with normal diet. At the end of the four weeks, Fasting the rats of four weeks control group and LPS group one day, anaesthetizing with 1％pentobarbital sodium(20mg/kg), collecting Abdominal aortic blood, Centrifugating with 3500r/min for using, Collecting the left lobe hepatic tissue and puting them in neutral formalin of 10%.Then paraffin imbedding, histological section, hematoxylin-eosin(HE) staining and SudanⅣstaining respectively. To deal the left rats in the same methods at the end of the ninth weeks.Results:1.Whether it is the three or six months of model group rats compared with normal rats, the level of alanine aminotrnsferase (ALT),Tumor necrosis factor-a (TNF-a),Fasting insulin (FINS),Fasting plasm glucose(FPG),Insulin Resistance index(IRI),Lipopolysaccharide(LPS)in plasma is significant increased(P<0.05), The level of alkaline phosphatase (ALP) in 1% of the small intestine homogenate is also increased significantly(P<0.05).After HE staining of liver tissue, intestinal tissue,observed under light microscope, compared with the normal group, March, June model group were different degrees of liver steatosis, accompanied by inflammatory cell infiltration; Intestinal villus epithelium is also damaged, villus epithelial edema, partial deletion and erosion was formation, and chronic inflammatory cell infiltration can be seen. Compared with the March model group,the liver and intestine of june model group rats were more serious.2.Compared with four weeks control group, ALT, TNF-α, FINS, LPS in plasma tended to increase, IL-10 on a downward trend in the four weeks LPS group, but there was no significant difference(P>0.05).The nine weeks LPS group compared with nine weeks control group, TNF-α, FINS, FPG, LPS, and IRI in plasma was significantly higher, IL-10 significantly reduced and were significantly different(P<0.05). However, ALT only tended to increase with no significant difference (P> 0.05), APN also no significant difference (P> 0.05). Observating HE staining of liver tissue under light microscope, most of the four weeks LPS group without Lipid droplet, almost no inflammatory infiltration. Most of nine weeks LPS group have Lipid droplets, lots of small fat vacuoles within the cytoplasm, accompanied by inflammatory cell infiltration. Sudan IV staining showed a large number of small lipid droplets within the liver tissue of nine weeks LPS group.Conclusion:High-sucrose and high-fat diet can induce nonalcoholic steatohepatitis and insulin resistance in rats, Intestinal villus epithelium is also damaged, and the permeability of Intestinal is increasing, Rats with endotoxin alone can also induce non-alcoholic steatohepatitis and insulin resistance.