| Effect of dexamethasone on the fatty acid composition of total liver microsomal lipids and phosphatidylcholine molecular species. | |
| | |
MedLine Citation:
|
PMID: 11834086 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Dexamethasone depresses delta6 and delta5 and increases delta9 desaturase and synthase activities. Therefore, we investigated the effect on the fatty acid composition of microsomal liver lipids and phosphatidylcholine (PtdCho) molecular species. After 15 d of treatment we found a notable decrease in arachidonic acid, a small decrease in stearic acid, and increases of linoleic, oleic, palmitoleic, and palmitic acids in liver microsomal total lipids and PtdCho. The study of the distribution of the PtdCho molecular species indicated that 18:0/20:4n-6, 16:0/20:4n-6, and 16:0/18:2n-6 predominated in the control animals. Dexamethasone, as expected because of its depressing effect on arachidonic acid synthesis and activation of oleic and palmitic acid synthesis, evoked a very significant decrease in 18:0/20:4n-6 PtdCho (P<0.001) and an important increase in 16:0/18:2n-6. The invariability of 16:0/20:4n-6 PtdCho could be related to the antagonistic effect of arachidonic and palmitic acid synthesis. PtdCho species containing oleic acid were not significant. The bulk fluidity and dynamic properties of the microsomal lipid bilayer measured by fluorometry using the probes 1,6-diphenyl-1,3,5-hexatriene and 4-trimethylammonium-phenyl-6-phenyl-1,3,5-hexatriene showed no significant modification, probably owing to a compensatory effect of the different molecular species, but changes of particular domains not detected by this technique are possible. However, the extremely sensitive Laurdan detected increased lipid packing in the less-fluid domains of the polar-nonpolar interphase of the bilayer, possibly evoked by the change of molecular species and cholesterol/phospholipid ratio. The most important effect found is the decrease of arachidonic acid pools in liver phospholipids as one of the corresponding causes of dexamethasone-dependent pharmacological effects. |
| | |
Authors:
|
R R Brenner; S Ayala; H A Garda |
Related Documents
:
|
18160096 - Intra-specific variation in resting metabolic rate in mf1 mice is not associated with m... 7707336 - The effects of unsaturated fatty acids on helicobacter pylori in vitro. 6853446 - Lipid composition of zymomonas mobilis: effects of ethanol and glucose. 687626 - The distribution of molecular classes of phosphatidylglycerol in the membrane of achole... 9611766 - Prebiotic amino acid thioester synthesis: thiol-dependent amino acid synthesis from for... 3495276 - Effect of tolfenamic acid on the metabolism of the main connective tissue components in... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: Lipids Volume: 36 ISSN: 0024-4201 ISO Abbreviation: Lipids Publication Date: 2001 Dec |
Date Detail:
|
Created Date: 2002-02-08 Completed Date: 2002-08-13 Revised Date: 2009-11-19 |
Medline Journal Info:
|
Nlm Unique ID: 0060450 Medline TA: Lipids Country: United States |
Other Details:
|
Languages: eng Pagination: 1337-45 Citation Subset: IM |
Affiliation:
|
Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CONICET-UNLP, Facultad de Ciencias Médicas, Argentina. rbrenner@atlas.med.unlp.edu.ar |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Dexamethasone / pharmacology* Fatty Acid Desaturases / antagonists & inhibitors, metabolism Fatty Acids / analysis* Glucocorticoids / pharmacology Lipid Metabolism* Lipids / chemistry Male Microsomes, Liver / drug effects*, metabolism* Phosphatidylcholines / chemistry, metabolism* Rats Rats, Wistar |
| Chemical | |
Reg. No./Substance:
|
0/Fatty Acids; 0/Glucocorticoids; 0/Lipids; 0/Phosphatidylcholines; 50-02-2/Dexamethasone; EC 1.14.19.-/Fatty Acid Desaturases |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Dietary alpha-linolenic acid lowers postprandial lipid levels with increase of eicosapentaenoic and ...
Next Document: Analysis of molecular species of peroxide adducts of triacylglycerols following treatment of corn oi...