Synaptosomal cholesterol and phospholipid levels in several mouse strains differentially sensitive to ethanol

The influence of chronic ethanol treatment on synaptosomal plasma membrane (SPM) cholesterol and phospholipid levels was determined in C57BL, Swiss Webster, DBA and BALB-C mice. A significant increase in SPM cholesterol after chronic ethanol treatment was observed only in C57BL mice. No change in either SPM cholesterol or C/P ratios was observed in the other three mouse strains tested, albeit all strains were rendered tolerant to ethanol as judged by ethanol-induced hypothermia, sleep time and blood ethanol upon awakening. It is concluded that an increase in SPM C/P ratio is not a necessary concomitant of behavioral or neurophysiological tolerance resulting from chronic ethanol consumption. In other studies, the possible relationship between SPM C/P ratios and initial neurosensitivity to ethanol was assessed in eight different mouse strains as well as two selected lines of mice. None of the individual mice had been tested previously with ethanol. No meaningful correlations could be made when the SPM C/P ratios of these strains were compared to either ethanol-induced sleep time, blood ethanol upon awakening or hypothermia. Therefore, genetic differences in SPM C/P ratios do not appear to be functionally related to phenotypic initial neurosensitivity to ethanol.