| Popis: |
Membrane lipid compositional changes have recently been shown by us to be at least partially responsible for the apparent tolerance to the membrane-fluidizing effects of ethanol [D. A. Johnson, N. M. Lee, R. Cooke and H. H. Loh, Molec. Pharmac . 15 , 739 (1979)]. Because not all effects of ethanol are generalizable to all strains and species, we attempted to determine whether these lipid compositional changes are related to the anesthetic actions of ethanol. Consequently, the effects of ethanol on the fluidity of reconstituted membranes formed from lipid extracts of synaptic membranes from tolerant C57BL/6J mice and Sprague-Dawley rats were assessed by using the fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene, incorporated into the membranes, as a relative index of fluidity. We observed apparent tolerance to the fluidizing effects of ethanol in both the C57BL/6J mice and the Sprague-Dawley rats. Acute in vivo ethanol treatment did not alter ethanol-induced fluidity of the reconstituted membranes. The results further support the suggestion that the change in brain membrane lipid composition, responsible for the apparent tolerance to the membrane-fluidizing effects of ethanol, is related to tolerance to the anesthetic actions of ethanol. |
