Effects Of Different Medicine On Body Weight,Fat Mass,Fasting Serun Ghrelin Level Of High-Fat Diet Induced Obese Rats

Objective: To assess the effects of sibutramine, fenofibrate, metformin and topiramate on the body weight , fat mass, fasting serum glucose, insulin and ghrelin levels of high-fat diet induced obese Wistar rats, and to discuss the possible mechanisms of their effects.Methods : 57 3-week-age Wistar rats with body weight from 63.7gram to 99.9 gram were randomly divided into two groups: rats of one group received high-fat diet, and those of another group reveived normal diet. 19 weeks later, we got 35 obese rats (diet-induced obese rat, DIO rat) (mean weight 535.03±41.26 gram) ,15 obese resistance rat ( diet-induced obese resistance rat, DIO-R rat) ( mean weight 418.46±15.73 gram) and 7 normal rats (mean weight 496.43±55.43 gram) . Divide all of the 35 DIO rats into five groups randomly according to their body weight. Rats of these five groups were treated with water , sibutramine (10mg/kg), fenofibrate (83.4 mg/kg), metformin (400mg/kg) and topiramate (53.6mg/kg) individually. Both DIO-R rats and normal rats went on receiving their foregoing diet, and the DIO rats received high-fat diet as of old. 8 weeks later, all rats were executed. Scale the length from nose to anus of rats in order to calculate the Lee's index, collect the fasting blood samples and measure the viscus fat. Detect the fasting serum ghrelin and insulin levels by EIA and RIA respectively.Results: (1) The body weight and fasting insulin level of DIO-R rats weremarkedly lower than those of normal cohort, and the HDL-C level was markedly higher. Fasting serum ghrelin level has the trend of being higher than that of the normal rats.(2) Fasting serum ghrelin level of DIO-R rats and normal rats was prominently negatively correlated to fasting insulin level ^ TG> fasting glucose and fat mass according to simple correlation. But multiple regression analysis showed that none of them can determine the level of fasting ghrelin.(3) All of the four medicine could induce body weight loss ,and the fat mass of the groups of rats treated by sibutramine and fenofibrate decreased notably. Compared with fasting serum ghrelin level of obese cohort, that of rats treated by metformin didn't change, meanwhile those of groups treated by sibutramine and topiramate became higher and that of fenofibrate group became lower, although there were no statistical significances between them.(4) Fasting serum ghrelin level of rats treated by medicine was prominently negatively correlated to fasting insulin level ^ TG and Lee's index according to simple correlation. Multiple regression analysis showed that fasting insulin level can affect the fasting ghrelin level, meanwhile TG level and Lee's index can't. Partial correlation analysis revealed that the relationship between TG > Lee's index and ghrelin level were cooperated with the effect of fasting insulin.Conclusions: All of sibutramine ^ fenofibrate ^ metformin and topiramate were effective on the treatment of obesity, furthermore, the effects of sibutramine and fenofibrate on reducing fat mass were noticeable. Fasting serum ghrelin levels of rats treated by sibutramine and topiramate had the trend to become higher than that of the cohort, and that of fenofibrate-treated rats became lower. Metformin had almost no effect on the ghrelin level.