Differential expression of nicotinamide adenine dinucleotide phosphate-diaphorase in hypothalamic areas of obese Zucker rats

Several studies have suggested that the activity of nitric oxide synthase ( NOS) may be involved in the regulation of food intake in the genetically ob ese Zucker rats. In the present study, we investigated the expression of NO S in various hypothalamic regions of obese and lean Zucker rats using nicot inamide adenine dinucleotide phosphate (NADPH)diaphorase histochemistry. Ob ese Zucker rats showed significantly lower staining intensities of NADPH-di aphorase-positive neurons in the paraventricular nucleus (PVN), lateral hyp othalamic area (LHA) and ventromedial hypothalamic nucleus (VMH) than lean Zucker rats did. The differences in staining intensities between obese and lean Zucker rats were large in both the PVN and LHA, but such differences w ere relatively small in the VMH. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.