Morphological changes of liver in obese rats induced by high fat diet and its significance

Objective To observe the liver histology change of obesity rat induced by high fat diet and discuss its significance. Methods The rats were divided into 2 groups:12 obesity rats induced by high fat diet and 8 rats for control. Then the fasting blood glucose, lipid, blood uric acid, insulin level were tested while BMI, HOMA-IR and ISI were calculated at 14 week. Also the HE staining of the liver tissue was performed. Results The baseline parameters including gender, body weigh, body length, tail length and Lee’s Index were similar between the two groups (P>0.05) . But after 14 weeks, the body weigh, body length and Lee’s Index of the obesity rats were higher significantly than the normals[ (367.92±88.88) g vs (252.5±59.47) g, (23.14±2.18) cm vs (20.81±1.71) cm, (328.18±9.82) vs (265.00±38.17) , (P<0.05) ]. The fasting blood glucose of obesity group was higher than that of control group, but the HDL level of obesity group was lower than that of control group[ (7.00±1.81) mmol/L vs (4.21±1.13) mmol/L, (1.24±0.14) mmol/L vs (1.41±0.15) mmol/L, (P<0.05) ]. The insulin, triglycerides, cholesterol, LDL, urimic acide, HOMA-IR and ISI were not different between the two groups. The balloon degeneration and fatty degeneration of the liver tissue were observed under light microscope at the obesity group. Conclusion The balloon-like changes and steatosis of the liver tissue, as well as the high blood sugar and high-density lipoprotein, were the basis of obesity induced abnormal metabolism including fatty liver and glycolipids. Key words: Obesity; Rat; Insulin resistance; Pathology