Effects of Hypothalamic Arcuate Nucleus NPY5 Receptor Signaling Pathway on Feeding Regulation in Normal Rats and Obesity Rats

Abstract

Objective: In this study, we mainly observed the expression of NPY5 receptor in the hypothalamic arcuate nucleus (ARC) in normal rats and obesity rats, and the effect of the NPY5 receptor agonist [D-Trp34] NPY and NPY5 Receptor antagonist CGP-71683 on Food Intake in the normal and obesity rats . Methods: Immunohistochemistry was used to observe the expression of NPY5 receptor in ARC of normal rats and obesity rats. RT-PCR was used to observe the expression of NPY5 receptor mRNA in ARC of normal and obesity rats. The NPY5 receptor agonist [D-Trp34] NPY and NPY5 receptor antagonist CGP-71683 were injected into the ARC via intraventricular catheters to observe the food intake of rats. Results: The results of immunohistochemistry and RT-PCR experiments showed that the expression of NPY5 receptor was observed in the hypothalamus ARC, and the expression of NPY5 receptor in obesity rat was significantly higher than that in normal rats. Compared with the normal saline group, the food intake of the normal rats and obesity rats significantly increased during the 0-4h after the injection of NPY into the ARC. Similarly, the food intake of the normal rats and obesity rats significantly increased during the 0-4h after the injection of NPY5 receptor agonist [D-Trp34] NPY into the ARC. The NPY5 receptor antagonist CGP-71683 could block the NPY and NPY5 receptor agonist [D-Trp34] induced the feeding. After injection of NPY and NPY5 receptor agonist [D-Trp34] in the ARC of obesity rats, the food intake was significantly higher than in normal rats during 0-4 h. Conclusion: The NPY5 receptor in the hypothalamus ARC is involved in the regulation of feeding behavior and may be related to the formation of obesity.