Study On Insulin Protective Effects In Liver Injury Of Endotoxemic Infant Rats

Objective:In order to investigate NF-κB,TNF-αand IL-6 roles on LPS-induced hepatocyte injury in infant rats,and whether insulin have protective effects in endotoxemic liver injury,established endotoxemia infant rat models,and detected the activation level of NF-κB and the level of TNF-αand IL-6 in liver cells.Method:72 wistar rats of 18-day-postnatal were randomly divided into normal control group(NS,n=8),lipopolysaccharide group(LPS,n=32) and insulin group(LPS plus insulin,n=32).According to the survival time after injected lipopolysaccharide,the later two group were divided into 2h,6h,12h and 24h secondary groups,each secondary group had 8 rats.LPS group and insulin group infant rats were injected lipopolysaccharide into abdominal cavity at a dose of 5mg/kg,insulin group rats were given insulin(4IU/kg) by intradermally inject at the same time,the normal control group were injected the same dose sodium chloride into abdominal cavity.We collected the liver essay to make into paraffin section and homogenate.The TNF-αand IL-6 levels in liver homogenate were detected by ELISA and the activation degree of NF-κB detected by immunohistochemistry.At the same time,we observed liver pathological change of these rats by light microscope and electronic microscope, and evaluated the inure degree of liver,in addition,the blood glucose and serum ALT were detected by biochemistry methods.Results:1.Histological changes:The liver tissue of LPS group rats were damaged seriously.Under light microscope,LPS group showed liver cells swelling,vacuolar degeneration,inflammatory cell infiltration in header district, the most obvious damage appeared in 6h groups,score level of injury compared with normal control group were significant differences in statistically,insulin groups have lighter damage than LPS groups.2.Blood glucose level:In insulin group the blood glucose level were lower than that of the normal control group and LPS group at 2h and 6h(p＜0.05),meanwhile,there were no distinction among the groups at 12h and 24h(p＞0.05).3.ALT levels:ALT levels were no difference among the groups at 2h(p＞0.05),LPS group was higher than the normal control group at 6h(p＜0.05).At 12h,LPS group and the insulin group was higher than the normal control group(p＜0.05).At 24h,the highest was LPS group.4.Hepatocyte NF-κBp65 protein expression:The percentage of nuclear NF-κBp65 positive cells in LPS group was higher than the normal control group (p＜0.05),insulin group at 2h and 6h were significantly lower than the LPS group(p＜0.05).5.Liver homogenate TNF-α,IL-6 levels:The level of TNF-αand IL-6 in liver homogenate in LPS group was higher than normal control group and insulin group at 6h and 12h,(p＜0.05).Conclusion:1.Endotoxemia can cause the damage of liver,lead to hepatocyte damages and liver function changes,indicating that liver is one of the organs which involved in severe infection.2.The activation of NF-κB might participate in the liver damage in endotoxemia,and its mechanism might be led to excess creation of inflammation mediators TNF-αand IL-6 which caused the inflammatory liver damage.3.Insulin had protective effects for endotoxemic liver injury,its mechanism might be through reducing NF-κB activation, reducing TNF-αand IL-6 synthesis and release,lowing blood glucose during the stress response state,however,the exact mechanism need more study.