Effects Of High-Fat Diet And High-Protein Diet On Oxidative Stress Of Rats In Development Period

PrefaceRecent survey shows that the irrational structure of children's diets is still prominent in China.The man who has got chronic non-communicable diseases is becoming younger.Studies have shown that early nutritional status related to the occurrence of chronic diseases in future,such as obesity,cardiovascular disease and type 2 diabetes.Oxidative stress is one of the important mechanisms of many chronic diseases.Many scholars,at home and abroad,have confirmed that high-fat diet could improve the level of oxidative stress.However,at present,the relationship between high-protein diet and oxidative stress is still controversial.Furthermore,it has been reported few about the effect of high-protein diet on oxidative stress.By feeding rats with high-fat diet or high-protein diet in development period,we want to explore its impact on oxidative stress and mechanism,and provide a theoretical basis to prevent the occurrence of adult diseases.MethodsAccording to body weight,48 Male Wistar rats,5～6 weeks,were randomly divided into there groups,fed with basic diet,high-fat diet and high-protein diet for 12 weeks.Feeding and drinking water freely.At the end of the 6th week,8 rats were randomly selected from every group,and others were fed until the end of experiment. The inferior vena cava of rats was bleed.The brain,liver,kidney,perirenal fat and epididymal fat of rats were separated and weighed.Total superoxide dismutase(T-SOD) and catalase(CAT),glutathione(GSH) and malondialdehyde(MDA) were measured.Results1.Case of feeding rats Compared with control group,food intake of high-fat group was lower(P＜0.01), calorie intake of it was higher(P＜0.01,P＜0.05) during experiment.Food titer of it had no statistically significant difference with control group on the 6th week(P＞0.05), which was higher on the 12th week(P＜0.05).Food intake,calorie intake and food titer of high-protein group had no statistically significant differences with control group during experiment(P＞0.05).2.Body weight of ratsThe body weight of rats has been increasing over time.But the body weights of three groups had no statistically significant differences during experiment(P＞0.05).3.Organ index and the content of visceral fat of ratsBrain index,liver index and kidney index of three groups had no statistically significant differences on the 6th week and the 12th week(P＞0.05).Compared with control group,the content of visceral fat of high-fat group increased on the 6th week and the 12th week(P＜0.01,P＜0.05).The content of visceral fat of high-protein group increased on the 6th week(P＜0.05),but had no statistically significant difference with control group on the 12th week(P＞0.05).4.Markers of oxidative stress in blood of ratsCompared with control group,on the 6th week and the 12th week,CAT activity in serum of high-fat group and high-protein group significantly decreased(P＜0.01).T-SOD activity,the levels of GSH and MDA in blood of three groups had no statistically significant differences on the 6th week and the 12th week(P＞0.05).5.The level of GSH and MDA in brain,liver and kidney of ratsCompared with control group,on the 6th week,the level of GSH in brain and kidney of high-fat group increased(P＜0.01,P＜0.05),which in kidney of high-protein group decreased(P＜0.01);the level of MDA in brain and liver of high-protein group increased(P＜0.01).On the 12th week,the level of GSH in kidney and liver of high-fat group decreased(P＜0.01);the level of MDA in brain and liver of high-fat group increased(P＜0.05);the level of GSH in liver and MDA in brain of high-protein group decreased(P＜0.01).Conclusion1.Although high-fat diet or high-protein diet can not increase the body weight and the organ weight of rats,but can increase visceral fat content.2.High-fat diet or high protein diet decreased T-SOD and CAT activity in serum with time;CAT is more sensitive to high-fat diet or high protein diet than SOD.3.Rats fed with high-fat diet or high-protein die have different levels of oxidative damage in brain,liver and kidney at different stages during experiment.Brain is more vulnerable to oxidative stress by high-fat diet,and kidney is more vulnerable to oxidative stress by high-protein diet.