Glucocorticoids and insulin: reciprocal signals for energy balance.
Signals that regulate long-term energy balance have been difficult to identify. Increasingly strong evidence indicates that insulin, acting on the central nervous system in part through its effect on neuropeptide Y (NPY), inhibits food intake. We hypothesized that corticosteroids and insulin might serve as interacting, reciprocal signals for energy balance, acting on energy acquisition, in part through their effects on hypothalamic NPY, as well as on energy stores. Because glucocorticoids also stimulate insulin secretion, their role is normally obscured. Glucocorticoids and insulin were clamped in adrenalectomized rats with steroid replacement and streptozotocin-induced diabetes. Glucocorticoids stimulated and insulin inhibited NPY mRNA and food intake. Glucocorticoids inhibited and insulin increased energy gain as determined by the change in body weight. When adrenalectomized diabetic rats were treated, corticosterone stimulated and insulin inhibited food intake, and, respectively, inhibited and increased overall energy gain. More than 50% of the variance was explained by regression analysis of the two hormones on food intake and body weight. Thus glucocorticoids and insulin are major, antagonistic, long-term regulators of energy balance. The effects of corticosterone and insulin on food intake may be mediated, in part, through regulation of hypothalamic NPY synthesis and secretion.
Department of Physiology, University of California, San Francisco 94143.
A M
AM
Strack
R J
RJ
Sebastian
M W
MW
Schwartz
M F
MF
Dallman
D000315:Adrenalectomy; D000595:Amino Acid Sequence; D000704:Analysis of Variance; D000818:Animals; D016375:Antisense Elements (Genetics); D001483:Base Sequence; D001786:Blood Glucose / Q000378:metabolism*; D001835:Body Weight / Q000187:drug effects; D003345:Corticosterone / Q000097:blood / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology*; D005247:Feeding Behavior / Q000187:drug effects; D006706:Homeostasis; D006801:Humans; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D017403:In Situ Hybridization; D007328:Insulin / Q000494:pharmacology* / Q000502:physiology; D008297:Male; D008969:Molecular Sequence Data; D009478:Neuropeptide Y / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000494:pharmacology; D012016:Reference Values
D016375:Antisense Elements (Genetics); D001786:Blood Glucose; D007328:Insulin; D009478:Neuropeptide Y; D012333:RNA, Messenger; D011994:Recombinant Proteins; D003345:Corticosterone