title: The effects of nicotine self-administration and withdrawal on concurrently available chow and sucrose intake in adult male rats.
abstract: Carbohydrate intake, preference, and taste thresholds may be altered in current and former cigarette smokers, which may mediate weight gain and risk for obesity in individuals who quit smoking. Attempts to model these effects in rodents have primarily used noncontingent nicotine administration. The purpose of this research was to characterize changes in chow and sucrose intake in rats during a 23-h access model of i.v. nicotine self-administration (NSA), in which rats lever-pressed for chow, sucrose, and nicotine under concurrent fixed-ratio (FR) 1 schedules. Male rats were assigned to one of three groups that differed in food and drug availability. The Nicotine C+S group had concurrent access to nicotine, chow, and sucrose. The Saline C+S group had access to saline, chow, and sucrose. The Nicotine C-Only group had access to nicotine and chow, but not sucrose. Changes in food intake and weight gain were assessed during baseline, NSA, and nicotine withdrawal (i.e., saline extinction). Weight gain was significantly slowed during NSA and increased during withdrawal, but did not differ between the nicotine groups. NSA produced a significant decrease in both chow and sucrose intake. Gradual tolerance to nicotine's effects on sucrose, but not chow intake, occurred. During withdrawal, chow and sucrose intake increased, with a larger percent increase in sucrose intake compared to chow. The proportion of total food intake from sucrose was greater at the end of withdrawal compared to baseline, indicating a history of nicotine intake changed dietary preference. Combined, these results indicate that sucrose intake is more resistant to nicotine's appetite suppressant effects and withdrawal from nicotine produces a greater increase in sweet food intake alongside general increases in chow intake. Changes in overall food intake in current and ex-smokers may lead to increased risk for obesity and other health problems, potentially limiting the benefit of quitting smoking.
authors.affiliation: Department of Medicine, Minneapolis Medical Research Foundation, 701 Park Ave., Minneapolis, MN 55415, United States; Department of Medicine, University of Minnesota School of Medicine, 420 Delaware St. SE, Minneapolis, MN 55455, United States. Electronic address: pgrebenstein@mmrf.org.
authors.forename: Patricia E
authors.initials: PE
authors.lastname: Bunney
authors.affiliation: Department of Medicine, Minneapolis Medical Research Foundation, 701 Park Ave., Minneapolis, MN 55415, United States.
authors.forename: Danielle
authors.initials: D
authors.lastname: Burroughs
authors.affiliation: Department of Medicine, Minneapolis Medical Research Foundation, 701 Park Ave., Minneapolis, MN 55415, United States.
authors.forename: Christine
authors.initials: C
authors.lastname: Hernandez
authors.affiliation: Department of Medicine, Minneapolis Medical Research Foundation, 701 Park Ave., Minneapolis, MN 55415, United States; Department of Medicine, University of Minnesota School of Medicine, 420 Delaware St. SE, Minneapolis, MN 55455, United States; Department of Psychology, University of Minnesota, N218 Elliot Hall, 75 E River Rd., Minneapolis, MN 55455, United States.
authors.forename: Mark G
authors.initials: MG
authors.lastname: LeSage
mesh_terms: D000704:Analysis of Variance; D018686:Anesthetics, Intravenous / Q000494:pharmacology; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D003216:Conditioning, Operant / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects*; D005108:Extinction, Psychological / Q000187:drug effects; D005247:Feeding Behavior / Q000187:drug effects*; D005518:Food Preferences / Q000187:drug effects*; D008297:Male; D008723:Methohexital / Q000494:pharmacology; D009538:Nicotine / Q000008:administration & dosage*; D018722:Nicotinic Agonists / Q000008:administration & dosage*; D051381:Rats; D012055:Reinforcement Schedule; D012646:Self Administration
chemical_list: D018686:Anesthetics, Intravenous; D018722:Nicotinic Agonists; D009538:Nicotine; D008723:Methohexital
keywords: Body weight; Concurrent access; Food intake; Multiple reinforcers; Nicotine self-administration; Sucrose