Glycerophosphate acylation by microsomes and mitochondria of normal and dystrophic human muscle.
The incorporation of [14C]glycerophosphate into phosphatidic acid, diacylglycerol, triacylglycerol and phosphatidylcholine by microsomes and mitochondria prepared from normal and dystrophic human muscle incubated in vitro in the presence of 0.3 mmol/l CDP-choline was measured. In mitochondria only phosphatidic acid and diacylglycerol are labelled; the rate of incorporation into these two compounds showed no difference between dystrophic and normal mitochondria. In dystrophic microsomes the incorporation into phosphatidic acid was delayed and decreased. No incorporation of glycerol into diacylglycerol, phosphatidylcholine and triacylglycerol could be measured. Thus in dystrophic muscle microsomes only PA was labelled during an incubation of up to 45 min. In both types of microsomes the concentration of endogenous free fatty acids and diacylglycerol was nearly identical. The level of phosphatidylcholine was 186 and 79 nmol/mg microsomal protein in normal and dystrophic muscle microsomes, respectively. Whether the results could be explained as secondary changes was discussed. Despite some unsolved problems the conclusion was drawn that a better explanation of the results is to assume a primary defect involving microsomal-bound phosphatidic acid phosphohydrolase and possibly glycerol-P-acyltransferases.
D000215:Acylation; D002648:Child; D004075:Diglycerides / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D005994:Glycerophosphates / Q000378:metabolism*; D006801:Humans; D008297:Male; D008861:Microsomes / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism*; D009136:Muscular Dystrophies / Q000378:metabolism*; D010712:Phosphatidic Acids / Q000378:metabolism; D010713:Phosphatidylcholines / Q000378:metabolism; D014280:Triglycerides / Q000378:metabolism
D004075:Diglycerides; D005227:Fatty Acids; D005994:Glycerophosphates; D010712:Phosphatidic Acids; D010713:Phosphatidylcholines; D014280:Triglycerides; C029620:alpha-glycerophosphoric acid