Increased alcohol preference and intake in nicotine-preferring rats

ABSTRACT

Background

Alcohol and tobacco are among the leading substances that are misused together and shared genetic vulnerability is likely. Increased susceptibility to nicotine self-administration has been shown in alcohol-preferring rat-lines. However, a nicotine-preferring (nP) rat-line has not been studied for alcohol preference.

Objectives

To evaluate alcohol preference and intake in male and female nP rats. We hypothesized that nP rats and females would drink more ethanol than control rats and males, respectively.

Methods

nP rats are being selectively outbred for high oral nicotine intake at Ege University. Seventeen nP (18^th generation) and 20 naïve female and male SD rats, not previously exposed to alcohol or nicotine, were used. Twelve-week-old rats were given intermittent access to 20% ethanol in a 2-bottle-choice-procedure for six weeks. After one week withdrawal, six weeks of oral nicotine self-administration was applied.

Results

nP rats drank significantly more ethanol than controls and their preference for ethanol over water was higher. Female rats’ ethanol intake was higher than males’. The nP rats’ nicotine preference and intake were higher than controls, and they gained less weight.

Conclusion

We have shown for the first time that nP rats also have high alcohol intake. Our results support the hypothesis that shared genetic factors may underlie concurrent addiction to nicotine and alcohol and have translational value in understanding their misuse. Considering the increased vulnerability for alcohol use disorder in smokers and sex differences observed, early preventive measures in families with a history of tobacco addiction, specifically targeting female members, could have public health benefits.

KEYWORDS:

• Genetic vulnerability
• nicotine preferring rats
• selective breeding
• alcohol
• addiction
• sex differences

Acknowledgements

We would like to thank Derya Kalkan (Undergraduate student in Medical School, Ege University) for excellent technical assistance.

Disclosure statement

The authors report no relevant disclosures.

Additional information

Funding

This work was supported by Ege University Research Fund, Number: 17 TIP 071.