Nicotine decreases blood alcohol concentration in neonatal rats

Background: Our previous findings suggested that the intragastric coadministration of alcohol and nicotine to neonatal rats resulted in a significant decrease from the predicted peak blood alcohol concentration (BAC). We hypothesized that the coadministration of alcohol and nicotine would produce a nicotine dose-related decrease in peak BAC and a change in the BAC time curve profile. Methods: Sprague-Dawley rat pups were given alcohol and nicotine simultaneously via intragastric infusion. Two sets of nicotine doses were used in two independent studies. The low doses of nicotine were examined after the study of high doses of nicotine administration because of the possible ceiling effects from these nicotine doses on lowering BACs. Results: The results not only confirmed that the peak BAC was lowered by nicotine, but also generated new findings showing that the profile of BAC time curve was affected by these doses of nicotine. Concerns about possible ceiling effects led us to conduct another experiment to examine the effects of lower doses of nicotine on BACs. Those results showed a significant decline in BACs after cotreatment with 0.5 or 1 mg/kg nicotine and less robust changes on the BAC curve profiles. Although the nicotine dose at 0.25 mg/kg/day did not affect significantly the overall BAC profile, it did lower the peak BAG. Conclusions: Nicotine is capable of lowering the peak BAC among neonatal rat pups. Furthermore, the pattern of the BAC time curve seems to be more affected by high doses of nicotine.