The Influence Of High-fat Diet On The Level Of Hypothalamic Corticotropin-releasing Hormone At Rat

Objective: High-fat diet can cause obesity, induce insulin resistance and lead to type 2 diabetes. Hypothalamus, the central of dominating the appetite and weight, is closely related with obesity. Whether the high-fat diet influents the expression of hypothalamic corticotropin-releasing hormone (CRH) is not clear, so the objective of this study is to study the influence of high-fat diet on the level of hypothalamic CRH.Methods: 50 Sprague-Dawley female rats (8 weeks old,190-210g) were randomly divided into the high-fat diet group and normal control group, rats were sacrificed after six weeks and blood and hypothalamus were analyzed .Biological and chemical colorimetry, radioimmunoassay and Western blotting were used to measure the levels of the fasting blood glucose, free fatty acids, triglycerides, total cholesterol, fasting blood insulin and hypothalamic CRH respectively.Results: the body weight of rats in the group of feeding with high-fat diet was obviously increaser than that in the control group after 4 weeks (P <0.05). The levels of fasting blood insulin, free fatty acids, triglyc erides and total cholesterol after 6 weeks in the rats of feeding with high-fat diet were 13.52±4.26m IU / L, 0.47±0.1mmol / L, 0.84±0.14mmol / L and 1.66±0.31mmol/L respectively, which were significantly higher than those in the control group, they were 10.28±2.61mIU / L, 0.38±0.07 mmol / L, 0.66±0.12 mmol / L and 1.37±0.26 mmol / L respectively, the difference were statistically significant(P <0.05).The level of the fasting blood glucose and the index of insulin resistance in the rats of feeding with high-fat diet and in the normal control rats were 5.92±1.03mmol / L vs 5.76±1.06mmol / L , 3.39± 0.76 vs 2.69±0.97 respectively, there was no statistical difference at the level of blood glucose (P>0.05), but the insulin resistance index was significantly higher in the former group than that in the later group (P <0.05). Western blot results showed that the level of CRH in the rats feeding with high-fat diet was significantly higher than that in the control rats, the values were 0.614±0.153 and 0.337±0.125 respectively (P <0.05).Conclusion: The high-fat diet can cause obesity, insulin resistance and promote hypothalamic CRH expression.