This study examined the effect of feeding either a bland cornstarch- based diet (BCD) or a highly palatable, high fat diet containing sucrose (HPD) on hypothalamic arcuate nucleus (ARC) gene expression for neuropeptide- Y (NPY). Male Sprague-Dawley rats received either BCD ad libitum, HPD ad libitum, HPD pair-fed to the caloric intake of the BCD, or the HPD at 60% of ad libitum HPD intake for 7 days. Animals receiving the HPD ad libitum consumed more calories and gained more weight than animals receiving the BCD (P < 0.001). The HPD did not affect ARC NPY mRNA levels, whether the subjects were allowed to overeat or pair-fed to the BCD (P > 0.05). However, feeding the HPD at 60% of ad libitum intake of the HPD, increased NPY mRNA levels in the ARC relative to the other treatments (P < 0.01). The present data are consistent with the view that NPY in ARC responds to energy deficits rather than to hyperphagia stimuli related to palatability.
Bibliographical noteFunding Information:
The authors are grateful to S.L. Sabol for generously providing the transformed cell stocks needed to produce the cDNA probes for proNPY. This research was supported by General Research Funds of the Department of Veterans Affairs, the National Institute of Diabetes and Digestive and Kidney Diseases Grant DK-50456 and by the National Institute of Drug Abuse Grant DA-03999.
- Arcuate nucleus
- Food restriction
- NPY mRNA
- Palatable diet