The effects of eating a high fat diet on sensitivity of female rats to ethanol

Abstract

Eating a diet that is high in fat or sugar can impact dopaminergic systems, the same pathways targeted by drugs of abuse. Rats eating a high fat laboratory chow are more sensitive to the behavioral effects of drugs of abuse, including cocaine and methamphetamine. However, it is not known if eating a high fat diet also enhances sensitivity of rats to alcohol. To address this gap in knowledge two experiments were conducted. In Experiment 1, 24 female Sprague‐Dawley rats eating either standard (18% kcal from fat) or high fat (60% kcal from fat) chow for 5 weeks were trained to drink ethanol solution. Training consisted of a daily 4‐hour session for 28 days. Following training, during the test phase, two bottles were presented (one containing 8% w/v ethanol and one containing water) while animals had continuous access to food. In Experiment 2, the development of locomotor sensitization to once weekly cumulative doses of 15% ethanol (0.5–2.0 g/kg; i.p.) was studied in 16 female Sprague Dawley rats eating the same types of chow used in Experiment 1 (high fat or standard). In Experiment 1, rats eating high fat chow consumed more milliliters of ethanol on average daily than rats eating standard chow; however, when accounting for body weight, this difference was no longer apparent. Experiment 2 is ongoing; however, based on previous work with psychomotor stimulants, it is anticipated that rats eating high fat chow will be more sensitive to ethanol‐induced locomotor sensitization. These results provide additional information related to the growing obesity epidemic and its potential relationship substance use disorder. Future directions will investigate the impact of diet on sensitivity of male rats to ethanol, in order to examine potential sex differences.Support or Funding InformationDisclosures: The authors have no conflicts to declare. The present study was supported by the National Institute on Drug Abuse (R25‐DA033613).