Dynamic modulation of mitochondrial inner-membrane lipids in rat heart by dietary fat.
A novel longitudinal feeding design was used to investigate the controlling influence of dietary fatty acids on the dynamic incorporation of fatty-acyl chains into phosphatidylcholine, phosphatidylethanolamine and cardiolipin in inner membrane of cardiac mitochondria. Rats were fed a polyunsaturated-fatty-acid-rich oil (soya-bean oil) for 12 days, crossed-over to a monounsaturated-fatty-acid-rich oil (rapeseed oil) for the next 11 days, then returned to soya-bean oil for 11 more days. Additional rats were fed either soya-bean oil or rapeseed oil only throughout. Rats were killed serially. Regression analysis was used to represent longitudinal flux in membrane lipid fatty-acid composition occurring with change in dietary fat. The fatty-acid composition of phosphatidylcholine, phosphatidylethanolamine and cardiolipin was influenced by dietary oil in a reversible way. Maximal diet influence was achieved in the 11-day cross-over period. Soya-bean oil to rapeseed oil cross-over caused the fatty-acid composition of phosphatidylcholine, phosphatidylethanolamine and cardiolipin to resemble that of rats fed rapeseed oil only. These changes were reversed by crossing back to soya-bean oil, indicating the dynamic state and short half-life of membrane phospholipid fatty-acyl chains. This report demonstrates for the first time in the whole animal fed diets adequate in all nutrients that subcellular membrane lipids rapidly respond to change in dietary fatty-acid balance. The system may be used to assess in vivo the significance of dietary fat in determining membrane physicochemical properties and biochemical functions.
D000818:Animals; D004041:Dietary Fats / Q000494:pharmacology*; D005224:Fats, Unsaturated / Q000494:pharmacology; D005227:Fatty Acids / Q000032:analysis; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008563:Membrane Lipids / Q000378:metabolism*; D008929:Mitochondria, Heart / Q000187:drug effects / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism*; D051381:Rats; D012044:Regression Analysis
D004041:Dietary Fats; D005224:Fats, Unsaturated; D005227:Fatty Acids; D008563:Membrane Lipids; D010743:Phospholipids