Beta-melanocyte-stimulating hormone potently reduces appetite via the hypothalamus in chicks.
The melanocortin system together with other appetite-related systems plays a significant role in appetite regulation. The appetite-related effects of one such melanocortin, beta-melanocyte-stimulating hormone (MSH), are well documented in rodents; however, its effects in the avian class are not thoroughly understood. Thus, we designed a study to determine the effects of i.c.v. beta-MSH injection on food and water intake, plasma corticosterone concentration, ingestive and non-ingestive behaviours, and hypothalamic neuronal activation using Cobb-500 chicks. Chicks responded to beta-MSH-treatment with a reduction in food and water intake; however when water intake was measured independently of food intake, it was not affected. beta-MSH-treated chicks also had increased plasma corticosterone concentrations and increased c-Fos reactivity in the periventricular, paraventricular and infundibular nuclei, and the ventromedial hypothalamus; however, the lateral hypothalamus was not affected. The effect on food intake is primary because behaviours that may be competitive with food intake were not increased in beta-MSH-treated chicks. Based on these results, we conclude that beta-MSH causes anorexigenic effects that are likely primarily mediated via stimulation of satiety-related hypothalamic nuclei in broiler-type chicks.
Smith
M L
ML
Department of Cellular, Molecular, and Systemic Physiology, Southern Illinois University School of Medicine, Carbondale, IL, USA.
Prall
B
B
Nandar
W
W
Cline
M A
MA
D000818:Animals; D000831:Animals, Newborn; D001066:Appetite / Q000187:drug effects*; D002645:Chickens; D003345:Corticosterone / Q000097:blood; D004326:Drinking / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D005247:Feeding Behavior / Q000187:drug effects; D005508:Food Deprivation / Q000502:physiology; D007031:Hypothalamus / Q000187:drug effects*; D007150:Immunohistochemistry; D007276:Injections, Intraventricular; D009994:Osmolar Concentration; D000521:alpha-MSH / Q000494:pharmacology; D019824:beta-MSH / Q000008:administration & dosage / Q000494:pharmacology*
D019824:beta-MSH; D000521:alpha-MSH; D003345:Corticosterone