Roux-en-Y gastric bypass increases intravenous ethanol self-administration in dietary obese rats

PLoS One. 2013 Dec 31;8(12):e83741. doi: 10.1371/journal.pone.0083741. eCollection 2013.

Abstract

Roux-en-Y gastric bypass surgery (RYGB) is an effective treatment for severe obesity. Clinical studies however have reported susceptibility to increased alcohol use after RYGB, and preclinical studies have shown increased alcohol intake in obese rats after RYGB. This could reflect a direct enhancement of alcohol's rewarding effects in the brain or an indirect effect due to increased alcohol absorption after RGYB. To rule out the contribution that changes in alcohol absorption have on its rewarding effects, here we assessed the effects of RYGB on intravenously (IV) administered ethanol (1%). For this purpose, high fat (60% kcal from fat) diet-induced obese male Sprague Dawley rats were tested ~2 months after RYGB or sham surgery (SHAM) using both fixed and progressive ratio schedules of reinforcement to evaluate if RGYB modified the reinforcing effects of IV ethanol. Compared to SHAM, RYGB rats made significantly more active spout responses to earn IV ethanol during the fixed ratio schedule, and achieved higher breakpoints during the progressive ratio schedule. Although additional studies are needed, our results provide preliminary evidence that RYGB increases the rewarding effects of alcohol independent of its effects on alcohol absorption.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Administration, Intravenous
  • Alcohol Drinking / adverse effects*
  • Alcohol-Related Disorders / etiology*
  • Alcohol-Related Disorders / physiopathology
  • Animals
  • Body Weight / physiology
  • Central Nervous System Depressants / administration & dosage*
  • Central Nervous System Depressants / pharmacology
  • Diet, High-Fat / adverse effects
  • Ethanol / administration & dosage*
  • Ethanol / pharmacology
  • Gastric Bypass / adverse effects*
  • Male
  • Obesity / complications
  • Obesity / physiopathology
  • Obesity / surgery*
  • Rats
  • Rats, Sprague-Dawley
  • Self Administration

Substances

  • Central Nervous System Depressants
  • Ethanol