Title: Ethanol-induced fluidization of brain lipid bilayers: required presence of cholesterol in membranes for the expression of tolerance.
Abstract: The effects of ethanol on fluidity of reconstituted membranes formed from lipid extracts of tolerant and control mice synaptosomal membranes were assessed by fluorescence polarization techniques. Ethanol was less able to fluidize reconstituted membranes of ethanol-tolerant mice than controls. Acute in vivo administration of ethanol did not alter ethanol-induced fluidization of the reconstituted membranes. Since increased membrane cholesterol has been suggested to account for tolerance, the cholesterol and trace nonpolar lipids from the lipid extracts were removed and then cholesterol was added back so as to equalize its level in all groups. Following removal of cholesterol, it was not possible to detect any differences between the tolerant and control groups. However, when the cholesterol was added back so that all groups had a cholesterol/phospholipid ratio of 0.54, i.e., the control group level, it was possible to measure differences between tolerant and control lipid extracts. These results suggest that changes in the lipid composition of membranes can account in part for tissue adaptation to ethanol-induced membrane fluidization. Moreover, while the presence of cholesterol in the membranes appears to be required for the expression of tolerance, the small changes in the cholesterol content of membranes observed following development of tolerance probably are not responsible for the attenuation of ethanol-induced membrane fluidization.
Publication Year: 1979
Publication Date: 1979-05-01
Language: en
Type: article
Indexed In: ['pubmed']
Access and Citation
Cited By Count: 142
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot