Differential immune responsiveness in mouse lines selectively bred for high and low sensitivity to ethanol. 
Natural killer cell activity was compared in the Long-Sleep and Short-Sleep mouse lines.  These mice, initially selected for their sensitivities to a hypnotic dose of ethanol, are also differentially sensitive to other agents which act through the benzodiazepine/GABA receptor chloride ionophore complex.  Natural killer cell activity was 40-59% lower in Short-Sleep when compared to Long-Sleep mice.  Flow cytofluorometric analysis demonstrated that the number of Nk-1+ cells was also lower in the spleens of Short-Sleep than Long-Sleep mice.  In addition, the incidence of 3-methylcholanthrene-induced tumors was significantly greater in Short-Sleep (85.7%) than in Long-Sleep (14.3%) mice.  These results suggest that the Long-Sleep and Short-Sleep mouse lines may represent a unique model to assess the physiological role of the benzodiazepine/GABA receptor chloride ionophore complex in the neural modulation of immune function.