The effects of high fat on central appetite genes in Wistar rats: A microarray analysis

BackgroundTo evaluate the effects of high fat on central appetite regulatory genes in Wistar rats by microarray.MethodsSixteen male Wistar rats were randomly assigned to control (15% energy from fat) and high-fat (60% energy from fat) diets for 12 weeks. Body weight and food intake were recorded. Plasma leptin, ghrelin and insulin were measured by radioimmunoassay method. The expression of 111 appetite regulatory genes in the hypothalamus was evaluated by microarray and six genes, including leptin receptor, insulin receptor, orexin, NPY, AgRP, MC-4R, were further evaluated by real-time RT-PCR.ResultsBody weight increased significantly in HF group compared with control group, whereas energy intake was similar in the two groups. HF had a time dependent effect on plasma leptin, but insulin and ghrelin level remained stable throughout the study. A positive relation was also found between body weight and plasma leptin (r = 0.88, P < 0.01). The expression of 27 appetite genes in the hypothalamus was significantly affected by HF diet. However, only the expression of leptin receptor was confirmed lower in HF group than that in control by real-time PCR, which suggested that lower expression of leptin receptor might be another reason for leptin resistance.ConclusionsHF diet fed rats demonstrated leptin resistance, which could be targeted for obesity treatment.