Role of hypothalamic neuropeptide Y gene expression in body weight regulation.
Hypothalamic neuropeptide Y (NPY) may be involved in the hyperphagia that follows food deprivation associated with significant weight loss. However, it is unclear whether NPY is involved in body weight regulation under more physiological circumstances. Consequently, we measured body weight, food intake, arcuate nucleus (ARC) NPY mRNA, serum glucose, and insulin in male Wistar rats after 48 h of food deprivation and various refeeding protocols. Food deprivation produced a twofold increase in NPY mRNA, whereas 3 days of ad libitum refeeding returned body weight and NPY mRNA to control. If hyperphagia was prevented for 5 days during refeeding, then neither body weight nor NPY mRNA normalized. There were strong negative correlations between ARC NPY mRNA and both loss of body weight and serum insulin levels. These data suggest that hypothalamic NPY gene expression plays a role in control of body weight under physiological conditions. The data further suggest that NPY mRNA may be decreased by peripheral insulin levels.
Davies
L
L
Department of Clinical Endocrinology, Westmead Hospital, NSW, Australia.
Marks
J L
JL
D000704:Analysis of Variance; D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000378:metabolism / Q000502:physiology*; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D004435:Eating; D005215:Fasting; D015870:Gene Expression; D006706:Homeostasis; D007031:Hypothalamus / Q000378:metabolism / Q000502:physiology*; D007328:Insulin / Q000097:blood / Q000378:metabolism; D000078790:Insulin Secretion; D008297:Male; D009478:Neuropeptide Y / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012044:Regression Analysis
D001786:Blood Glucose; D007328:Insulin; D009478:Neuropeptide Y; D012333:RNA, Messenger