Role of Ventromedial hypothalamus in high fat diet induced obesity in male rats: association with lipid profile, thyroid profile and insulin resistance

BACKGROUND: Ventromedial hypothalamus (VMH) plays a major role in food intake, obesity and energy homeostasis. There is a report of gender difference in energy balance with increased vulnerability of males to cardiac disease. PURPOSE: Body metabolism is greatly influenced by the diet we eat and some of the blood parameters like plasma glucose, insulin, lipid profile and thyroid profile depict a picture of energy homeostasis of the body. OBJECTIVE: The present study was conducted to assess the effect of VMH in high fat diet (HFD) induced obesity and its link with insulin, glucose, thyroid and lipid profile of male Wistar rats. METHODS: The male rats (n = 12) were given HFD for a period of 10 weeks to induce obesity. After obtaining a basal recording of food intake, body weight, glucose, insulin, thyroid and lipid profile, animals were divided into control and experimental group (n = 6 male in each). Experimental rats underwent electrolytic ablation of VMH whereas control rats underwent sham lesion. A post-lesion recording was taken at the end of four weeks. RESULTS: The rats had a greater food intake and more body weight gain after HFD schedule in both the groups. After VMH lesion, food intake increased further, only in experimental group. Plasma glucose, Insulin, HOMA - IR, total cholesterol (TC) and triglycerides (TG) were significantly increased compared to the pre-lesion values in experimental group (P<0.001). CONCLUSIONS: Ten week of HFD resulted in obesity. VMH appears to prevent the development of insulin resistance and hypercholesterolemia which influences the energy homeostasis in male rats after high fat diet.