Differences in appetite-stimulating effect of NPY, orexin and ghrelin among young, adult, and old rats

摘要

Aging is associated with a progressive decrease in appetite and food intake. The decline of food intake that often occurs in healthy elderly persons predisposes them to pathological weight loss and protein-energy malnutrition, thereby increasing the risk of morbidity or mortality. Orexin-A, NPY (neuropeptide Y), and ghrelin, which are appetite-stimulating peptides, are known to play a critical role in food intake. Centrally administered ghrelin is thought to regulate feeding and energy homeostasis through direct activation of the orexin and NPY pathways. In this study, to determine the mechanism of the age-associated decrease in appetite and food intake, the stimulatory effect of intracerebroventricular administration of these peptides on food intake was compared among young (4-month-old), adult (11-month-old) and old (24-27-month-old) male Wistar rats.