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Effects of ethanol on the remodeling of neutral lipids and phospholipids in brain mitochondria and microsomes

Authors :
María P. Carrasco
Carmen Marco
José M. Jiménez-López
Josefa L. Segovia
Source :
Neurochemistry International. 50:858-865
Publication Year :
2007
Publisher :
Elsevier BV, 2007.

Abstract

We have analyzed the effects of ethanol in vitro on the remodeling of neutral lipids and phospholipids in mitochondria and microsomes isolated from chick brain. We used three different fatty acyl-CoAs of similar chain lengths but different degrees of unsaturation. Our results demonstrate the existence of active mechanisms for acyl-CoA transfer into neutral lipids and phospholipids in both mitochondria and microsomes. The profile of fatty acid incorporation was clearly different according to the membrane and lipid fraction in question. Thus, in mitochondrial lipids, the remodeling processes showed a clear preference for the saturated fatty acid whilst the polyunsaturated one was the preferred substrate for microsomal lipid acylation. With regard to the effects of ethanol in vitro, we were able to demonstrate that exposure of the membrane to ethanol led to an increase in the incorporation of polyunsaturated fatty acid into triacylglycerol (TG) in both mitochondria and microsomes, indicating that it directly stimulates the acylation of diacylglycerol (DG) to give TG. This effect may then contribute to the widely reported stimulation of TG biosynthesis in cases of both acute and chronic ethanol ingestion. It is noteworthy that the exposure of microsomes to ethanol in vitro also stimulated the incorporation of oleoyl-CoA into the aminophospholipids phosphatidylethanolamine (PE) and phosphatidylserine (PS). We also demonstrate that both mitochondria and microsomes synthesize fatty acid ethyl esters (FAEEs) from fatty acyl-CoA, although there is a clear difference in preference for the fatty acid used as substrate in the esterification of the alcohol. Thus, mitochondria were capable of forming FAEEs from the polyunsaturated fatty acid whilst in microsomes the saturated fatty acid was the preferred substrate. In both types of membrane, FAEE production was lowest with the monounsaturated fatty acyl-CoA.

Details

ISSN :
01970186
Volume :
50
Database :
OpenAIRE
Journal :
Neurochemistry International
Accession number :
edsair.doi.dedup.....b820b8ed394d4d5b7c23144fe256ffbc
Full Text :
https://doi.org/10.1016/j.neuint.2007.02.007