Effects Of Visfatin On Feed Intake And Hypothalamic Appetite Regulatory Factors Of Egg-type Cockerels

Visfatin is a novel adipocytokine which using a differential display method that appears to mimic the action of insulin, which is preferentially produced by human abdominal visceral fat. According to the recenet researches, it plays a key role in animal appetite regulation, but the mechanism is still not clear. This research mainly through the detection of serum biochemical indexes, quantitative real-time PCR(q RT-PCR), and metabolomics analysis technology to detect the effects of central administration of Visfatin on feed intake and hypothalamic appetite regulation factor of egg-type cockerels, in order to explore the appetite regulation theory foundation of poultry further.Experiment 1 Effects of Visfatin on feed intake and blood biochemical index of egg-type cockerels13 day old egg-type cockerels were intraventricular injected with 0ng, 40 ng and 400 ng human recombinant Visfatin, the food intake was measured and the blood was obtained at 30, 60 and 90 min respectively after injection, determination of the levels of glucose, insulin, triglyceride, total cholesterol, high density lipoprotein cholesterol and low density lipoprotein in serum. The results show that, intraventricular injection of 40 ng and 400 ng Visfatin, the feed intake of egg-type cockerels after 60 min and 90 min were significantly increase; intraventricular injection of 40 ng and 400 ng Visfatin after 60 min and 90 min, the blood glucose levels in the serum of egg-type cockerels were increase, and showed a dose dependent; at the same time, after intraventricular injection 60 min, triglyceride, high density lipoprotein and low density lipoprotein concentration changed significantly. Therefore, Visfatin can promote the feed intake of egg-type cockerels, and participate in the regulation of carbohydrate and lipid in the serum.Experiment 2 Effects of Visfatin on the gene expression of appeti te regulation in the hypothalamu s of egg-type cockerelsApplication of quantitative PCR to study the effect of Visfatin on the expression of NPY, Ag RP, POMC, CART and AMPK which is the main feed regulation factor in the hypothalamus of egg-type cockerels. The results show that, after injection of 40 ng Visfatin 30 min and 60 min in hypothalamus, promote the ingestion of neuropeptide NPY and Ag RP relative expression were increased significantly, and inhibited the expression of neuropeptide CART gene significantly intake decreased significantly, and the effect continued to within 90min; at the same time, after intraventricular injection of 40 ng and 400 ng Visfatin 30 min and 60 min, the relative expression of AMPK in the hypothalamus was increased significantly, and the treatment of high concentration group was significantly higher than the low concentration group after 30 min. Therefore, Visfatin can promote the expression of NPY, Ag RP, and AMPK, and inhibit the expression of CART in the hypothalamus.Experiment 3 Effects of Visfatin on the metabolites of appetite regulation in the hypothalamus of egg-type cockerelsApplication of UPLC-MS technology to study the effect of Visfatin on the metabolites of appetite regulation in the hypothalamus of egg-type cockerels. The results show that, after intraventricular injection of different concentration of Visfatin could induce changes in metabolism the hypothalamus. Based on the pattern recognition analysis, screened glucose and lipid metabolism and energy balance related to the effect of glucose, beta hydroxy butyric acid, dihydroxyacetone, threonine, leucine and gamma aminobutyric acid were metabolites, and the content of these metabolites in hypothalamus were significantly increased compared with the control group.In summary, intraventricular injection of Visfatin can improve the feed intake of egg-type cockerels, regulate and control the appetite regulatory factors expression in hypothalamus, and involved in the regulation of carbohydrate and lipid metabolism and energy balance in the serum and hypothalamus. But effects of the same concentration of Visfatin on different indexes and the time of duration are different.