title: Megestrol acetate increases short-term food intake in zinc-deficient rats.
abstract: Rats offered a zinc-deficient (-Zn) diet voluntarily reduce their food intake within 3-4 days. Megestrol acetate (MA) is an appetite-stimulating drug used to treat cachexia of chronic diseases. In previous work, we found MA administration to male rats increased consumption of a -Zn diet. This approach would provide a useful tool for nutritional studies in which nutrient intake, except for zinc, would be maintained. The present study further examined the use of MA to increase consumption of a -Zn diet over a longer time period in both male and female rats. Rats were fed either a -Zn or a zinc-adequate (+Zn) diet. In Experiment 1, rats were treated orally with 0, 20, 50 or 100 mg MA/kg BW in corn oil for 21 days. MA stimulated intake of the -Zn diet in a linear manner. In Experiments 2 and 3, male and female rats, respectively, were fed the -Zn or +Zn diets and treated with 100 mg MA/kg BW for 21 days. In both experiments, MA administration increased intake of the -Zn diet to levels similar to the +Zn diet through Day 14. MA increased the hypothalamic neuropeptide Y (NPY) concentration in male rats, but did not affect serum IGF-I. MA administration improved growth of female but not male rats fed the -Zn diet. In females, serum IGF-I was not lower in zinc-deficient rats, which may have allowed the improved growth response with MA. Hence, MA administration may be a useful tool to increase consumption of a -Zn diet in short-term studies.
authors.affiliation: Department of Nutritional Sciences, University of Missouri-Columbia, Columbia, MO 65211, USA.
authors.forename: Patricia S
authors.initials: PS
authors.lastname: Williamson
authors.forename: Jimmy D
authors.initials: JD
authors.lastname: Browning
authors.forename: Ruth S
authors.initials: RS
authors.lastname: MacDonald
mesh_terms: D000818:Animals; D019167:Appetite Stimulants / Q000494:pharmacology*; D004032:Diet; D004435:Eating / Q000187:drug effects*; D004734:Energy Metabolism / Q000187:drug effects; D005260:Female; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D019290:Megestrol Acetate / Q000494:pharmacology*; D009478:Neuropeptide Y / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects / Q000502:physiology; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D012727:Sex Characteristics; D015430:Weight Gain / Q000187:drug effects; D015032:Zinc / Q000172:deficiency*
chemical_list: D019167:Appetite Stimulants; D009478:Neuropeptide Y; D007334:Insulin-Like Growth Factor I; D015032:Zinc; D019290:Megestrol Acetate