Laura E Rupprecht1, Alison D Kreisler2, Samantha R Spierling2, Giordano de Guglielmo2, Marsida Kallupi2, Olivier George2, Eric C Donny3, Eric P Zorrilla2, Alan F Sved4,5. 1. Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA. laura.rupprecht@pitt.edu. 2. Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA. 3. Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA. 4. Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA. 5. Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA.
Abstract
RATIONALE: The ability of nicotine to suppress body weight is cited as a factor impacting smoking initiation and the failure to quit. Self-administered nicotine in male rats suppresses weight independent of food intake, suggesting that nicotine increases energy expenditure. OBJECTIVE: The current experiment evaluated the impact of self-administered nicotine on metabolism in rats using indirect calorimetry and body composition analysis. METHODS: Adult male rats with ad libitum access to powdered standard rodent chow self-administered intravenous infusions of nicotine (60 μg/kg/infusion or saline control) in daily 1-h sessions in the last hour of the light cycle. Indirect calorimetry measured respiratory exchange ratio (RER), energy expenditure, motor activity, and food and water consumption for 22.5 h between select self-administration sessions. RESULTS: Self-administered nicotine suppressed weight gain and reduced the percent of body fat without altering the percent of lean mass, as measured by Echo MRI. Nicotine reduced RER, indicating increased fat utilization; this effect was observed prior to weight suppression. Moreover, nicotine intake did not affect motor activity or energy expenditure. Daily food intake was not altered by nicotine self-administration; however, a trend in suppression of meal size, a transient suppression of water intake, and an increase in meal frequency was observed. CONCLUSION: These data provide evidence that self-administered nicotine suppresses body weight via increased fat metabolism, independent of significant changes in feeding, activity, or energy expenditure.
RATIONALE: The ability of nicotine to suppress body weight is cited as a factor impacting smoking initiation and the failure to quit. Self-administered nicotine in male rats suppresses weight independent of food intake, suggesting that nicotine increases energy expenditure. OBJECTIVE: The current experiment evaluated the impact of self-administered nicotine on metabolism in rats using indirect calorimetry and body composition analysis. METHODS: Adult male rats with ad libitum access to powdered standard rodent chow self-administered intravenous infusions of nicotine (60 μg/kg/infusion or saline control) in daily 1-h sessions in the last hour of the light cycle. Indirect calorimetry measured respiratory exchange ratio (RER), energy expenditure, motor activity, and food and water consumption for 22.5 h between select self-administration sessions. RESULTS: Self-administered nicotine suppressed weight gain and reduced the percent of body fat without altering the percent of lean mass, as measured by Echo MRI. Nicotine reduced RER, indicating increased fat utilization; this effect was observed prior to weight suppression. Moreover, nicotine intake did not affect motor activity or energy expenditure. Daily food intake was not altered by nicotine self-administration; however, a trend in suppression of meal size, a transient suppression of water intake, and an increase in meal frequency was observed. CONCLUSION: These data provide evidence that self-administered nicotine suppresses body weight via increased fat metabolism, independent of significant changes in feeding, activity, or energy expenditure.
Entities:
Keywords:
Energy expenditure; Indirect calorimetry; Oxymax; Respiratory exchange ratio
Authors: Dean Kirson; Michael Q Steinman; Sarah A Wolfe; Samantha R Spierling Bagsic; Michal Bajo; Suhas Sureshchandra; Christopher S Oleata; Ilhem Messaoudi; Eric P Zorrilla; Marisa Roberto Journal: J Neurosci Res Date: 2021-10-22 Impact factor: 4.433
Authors: Michael Q Steinman; Dean Kirson; Eric P Zorrilla; Marisa Roberto; Sarah A Wolfe; Sophia Khom; Shannon R D'Ambrosio; Samantha R Spierling Bagsic; Michal Bajo; Roman Vlkolinský; Noah K Hoang; Anshita Singhal; Suhas Sureshchandra; Christopher S Oleata; Ilhem Messaoudi Journal: Mol Psychiatry Date: 2020-10-21 Impact factor: 15.992