고지방식이를 섭취한 흰쥐에서 시상하부 Neuropeptide Y- 면역반응 신경세포와 장내 Cajal 세포의 변화

Abstract

Neuropeptide Y (NPY) is a potent orexigenic neurotransmitter in the hypothalamus and induces hyperphagic response. Several antagonists of NPY have been developed, but their effects on suppression of food intake are limited. The interstitial cells of Cajal (ICC) are involved in the regulation of gastrointestinal motility. The aim of the study was to assess the changes in NPY immunorectivity in the hypothalamus and the changes in ICC in the small intestine of the rats fed high-fat diets (HFD). Male Sprague-Dawley rats (200~250g body weight ) were randomly divided into two groups: control group (normal chow diet for 6 weeks), and HFD group (rodent Diet with 60%kcal fat for 6 weeks). The immunoreactivities of NPY in the hypothalamus and ICC in the small intestine were evaluated after every feed for 6 weeks. NPY immunoreactivity was observed strongly in the hypothalamic nuclei in the HFD group compared to the control group. The numbers of NPY-immunoreactive (IR) cells were significantly higher in the paraventricular hypothalamic nucleus in the HFD group than in the control group. In the region of Auerbach’s plexus (AP) of small intestine, the staining intensity of the ICC-IR cells was reduced in the HFD group compared to the control group. The numbers of the ICC in the small intestine with HFD, including ICC in the inner circular and outer longitudinal muscle were significantly lower than in the control group. Based on the results, it can be suggested that the action of NPY in the hypothalamus may become resistant after a HFD, and the loss of ICC in the small intestine after a HFD is probably functionally significant in gastrointestinal motility.