Influence of diet composition on food intake and neuropeptide Y (NPY) gene expression in goldfish brain.

摘要

In this study, goldfish demonstrate preference for high carbohydrate and high fat diets, with no preference shown for high protein diets. Fish fed high (45% and 55%) carbohydrate (CHO) diets for 1 and 4 weeks exhibited decreased NPY gene expression in telencephalon-preoptic area (TEL-POA) and optic tectum-thalamus (OT-THAL) compared to fish fed low CHO (35% and 40%) diets. In hypothalamus (HYP), NPY gene expression was significantly increased after 1 week in fish fed both low and high CHO diets compared to control diet (40% CHO); after 4 weeks, the pattern in HYP was reversed. Fish fed a high fat (9%) diet had low NPY gene expression in TEL-POA after 1 and 4 weeks; however, HYP NPY expression was increased in fish fed a low (3%) fat diet after 1 week, and 2% and 3% fat diets after 4 weeks. In OT-THAL, NPY gene expression was decreased in fish fed a 2% fat diet for 1 week, and increased after 4 weeks. Feeding diets with different protein contents for 1 or 4 weeks did not influence NPY gene expression in goldfish brain. The results demonstrate, for the first time in a lower vertebrate, that NPY gene expression in goldfish brain is influenced by macronutrient intake.