Interactions of ethanol and nicotine at the receptor level.

Several studies have demonstrated that alcohol use is generally accompanied by an increase in smoking in humans. In rats, nicotine administration increases alcohol consumption. Genetic evidence from animal studies also suggests ethanol-nicotine interactions in that mouse lines that were selectively bred for differential sensitivity to ethanol also differ in sensitivity to nicotine. In addition, animals that have been chronically treated with alcohol are cross-tolerant to some of the actions of nicotine and chronic nicotine-treated animals are cross-tolerant to alcohol. This review summarizes the data which indicate that lipids and lipid membranes modify the binding of nicotinic agonists and antagonists to non-neuronal nicotinic receptors as well as modifying the function of these well characterized receptors. These results suggest that studies of ethanol disruption of membrane lipid regulation of brain nicotinic receptor binding, structure, and function may provide insights into why humans frequently use and abuse alcohol and tobacco together.