HYPOTHALAMIC NEUROPEPTIDE-Y AND GALANIN IN OVERWEIGHT RATS FED A CAFETERIA DIET

We evaluated neuropeptide Y (NPY) and galanin (GAL) immunoreactivity ( IR) and mRNA in the paraventricular and arcuate nucleus, respectively, in rats that became overweight (Ov) or not (NOv) when fed a cafeteria diet. After 2 months of diet, NOv rats showed a significant increase in NPY IR, whereas Ov rats showed a significant increase in GAL mRNA l evels. None of these changes was present in rats overfed for 6.5 month s. These differential changes in hypothalamic GAL and NPY transmission s may contribute to the different susceptibility of the two rat subpop ulations to the weight-promoting effects of the hypercaloric diet. (C) 1998 Elsevier Science Inc.