Induction Method of Non-Alcoholic Fatty Liver Model in Obesity and Obesity-Resistant Rats

Objective: To establish obesity and obesity-resistant rats model of non-alcoholic fatty liver. Methods: 140 male Sprague Dawley rats were randomly divide into group control(20) and model(120), maintained a standard diet and high-energy-fat diet for 8 weeks, respectively. Then the rats of high-energy-fat group were divided into 2 groups s: NO and NOR groups. The rats of body mass higher than nomal +1.96 times standard deviation were divided into NO group and the rats of body mass higher than nomal +1.0 times standard deviation were divided into NOR group. The general conditions and weight changes were dynamically observed for 8 weeks, and then killed 8 rats of different group. The pathological changes of liver tissues were observed by HE staining. The following indexes were compared among the three groups, including serum levels of triglyceride(TG), total cholesterol(TC), alanine aminotransferase(ALT), aspartate aminotransferase(AST) and liver index, body fat ratio. Results: Starting from the fifth week,the weights of rats were significantly decreased in group control and NOR as compared with those in group NO(P 0.01). The serum levels of ALT, TG, liver weight and index, body fat ratio in group NO and NOR were markedly higher than control(P 0.05). The TC, TG levels and weight of liver in group NO were increased significantly compared with group NOR(P 0.05). And there was no significantly difference between group NO and NOR in liver index and body fat ratio. Light microscopy showed a great number of fat vacuoles in liver cell of group NO and NOR. Conclusion: The obesity and obesity-resistant rat model of non-alcoholic fatty liver can be successfully established within 8 weeks and basically simulating the occurrence and progression of non-alcoholic fatty liver in human beings.