The Study Of The Relationship Between DPPâ…£ And Fatty Liver Disease In Obese Children And Young Rats

Part1 Establishment of a young rat model with non-alcoholic fatty liver disease and the study of liver histopathological changes and immunoreactivity of DPPâ…£Objective:To induce liver steatosis by giving high fat diet. To detect the influence of high-fat diet on body weight, body mass index, liver enzymes and pathological changes of liver cells in order to establish non-alcoholic fatty liver (NAFLD) animal model. To study serum activity of DPP IV, DPP IV immunoreactivity of rat with nonalcoholic fatty liver, and the correlation between DPPâ…£and total cholesterol (TC), triglycerides (TG), high density lipoprotein (HDL), low-density lipoprotein (LDL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), body weight, fasting blood glucose (FBG), fasting insulin (FIN), etc. Methods:24 weaned rats, including 12 males and 12 females, divided inio 2 groups randomly. Two different diet were given to the two different groups, one is the normal diet for a group with 12 rats (6 males and 6 females); one is high fat diet for a group with 12 rats (6 males and 6 males). Serum activity of DPP IV were measured after 4 weeks feeding, the weight, length, abdominal circumference, ALT, AST, TC, TG, HDL, LDL were detected at the same time. After the rats were killed, the liver wight were wighted and then calculated the liver index. To observe the degree of liver tissue steatosis by HE staining and the expressions of DPPâ…£in liver tissue were examined using immunohistochemistry. Results:1. The abdominal circumference, body weight, liver weight, liver index in model group were significant higher than the control group (P<0.05). Compared with the control group, the liver weight of model group increase and the color become shadow; HE staining showed that:compared with the control group, liver cells of model group display light, moderate to severe steatosis and ballooning degeneration; Liver cells of model group filled cavity, and showed a significant hepatic steatosis.2. Compared with the control group, serum TC, TG, HDL, LDL, ALT, AST, DPP IV, FBG, FIN of model group rats were significant higher(P<0.05); The DPP IV immunoreactivity of liver tissue in modal group was stronger than the control group.3. Serum activity of DPP IV in model group has a positive correlation with ALT and has no correlation with other factors, such as body weight, AST, blood lipids (TC, TG, HDL, LDL), FBG and FIN. Conclusion:1. High-fat diet for 4 weeks, the model group rats appeared obesity, high blood TG, TC, low HDL, elevated liver index, mild to severe liver steatosis and so on, which is the same clinical features of NAFLD children, while the liver index increased and liver histopathology appeared that the liver cells showed mild to severe fatty degeneration, indicating that NAFLD rats model was induced by high fat diet successfully.2. Serum activity of DPPâ…£significantly higher in model group and it has positive correlation with ALT; DPPâ…£immunoreactivity of the control group was stronger than the model group and rats with more severe hepatic steatosis had poorer DPPâ…£immunoreactivity, suggesting that DPP IV is related to non-alcoholic fatty liver.Part2 the study of activity of serum DPPâ…£in the obese children with non-alcoholic fatty liver diseaseObjective:To study the relationship between serum activity of DPP IV and non-alcoholic fatty liver disease. Methods:34 obese children with non-alcoholic fatty liver disease (the children with abnormal glucose metabolism is excluded) and 50 normal children (control group) were measured height (H), weight (W), waist circumference, hip circumference, and calculated body mass index (BMI), waist to hip ratio; to detect blood alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), high density lipoprotein (HDL), DPP IV, fasting blood glucose (FBG). And the data were analyzed statistically. Results:The serum activity of DPP IV in non-alcoholic fatty liver group was significantly higher than control group (P<0.05); correlation analysis suggested that there is a positive correlation between serum DPP IV and ALT(P<0.05). Conclusions:Serum DPP-4 activity should be considered as a novel non-alcohol liver disease biomarker.