ABSTRACT
SIGNIFICANCE: Alcohol drinking and nicotine vaping often co-occur and dependence on both substances is common. However, the impact of nicotine vaping on alcohol consumption is not fully understood. METHODS: We examined the effects of nicotine vaping on ethanol drinking in female and male C57BL/6 J mice using an electronic nicotine delivery system and intermittent access two-bottle choice (IA-2BC) drinking. Mice were exposed to electronic nicotine vapor (3%) or propylene glycol/vegetable glycerol (PG/VG) control for 3 h sessions daily for 4 weeks and voluntary alcohol consumption was monitored. Nicotine vapor exposure was stopped and voluntary alcohol drinking was measured for a 2 week abstinence period. We also examined the effects of alcohol and nicotine on locomotion, temperature, and nicotine metabolism. RESULTS: Following acute nicotine vapor exposure, alcohol drinking was increased in males but not in females. Thermoregulation was disrupted following nicotine vapor exposure and voluntary drinking. Male and female mice displayed increased locomotor activity immediately following chronic nicotine vapor exposure, and an anxiolytic effect was seen in males. In nicotine vapor abstinence, female mice displayed increased alcohol consumption. Locomotor activity and anxiolytic effects remained elevated in male but not female mice. Female mice displayed higher levels of serum nicotine and hydroxycotinine, suggesting impaired metabolism following chronic drinking and nicotine vapor exposure. CONCLUSION: Collectively, these results suggest that while both male and female ethanol-drinking mice experience the stimulatory effects of nicotine vapor, only in males is there a parallel increase in ethanol drinking and only females display impairments in nicotine metabolism after drinking.
