Association of changes in lysophosphatidylcholine metabolism and in microsomal membrane lipid composition to the pulmonary injury induced by oleic acid.
Alterations in the lipid composition of lung microsomal membranes occur in oleic acid-induced respiratory distress. The marked decrease in the phosphatidylcholine/lysophosphatidylcholine molar ratio could be related with an altered metabolism of lysophosphatidylcholine in these membranes. Results revealed that the activity of phospholipase A increased whereas that of acyl-CoA:lysophosphatidylcholine acyltransferase decreased. Microsomal lysophospholipase activity remained unchanged. On the other hand, the microsomal enzyme system involved in the de novo synthesis of diacylglycerol was impaired, and cholinephosphotransferase activity was lowered. These changes in the activity of some membrane-bound enzymes were not caused by changes in the membrane lipid fluidity since lipid structural order parameter (SDPH) did not change and neither did the major factors on which the fluidity depends. The possible significance of microsomal lipid alterations in the pathogenesis of respiratory distress induced by oleic acid is discussed.
Casals
C
C
Department of Biochemistry, Faculty of Chemistry, Universidad Complutense, Madrid, Spain.
Herrera
L
L
Garcia-Barreno
P
P
Municio
A M
AM
D008243:1-Acylglycerophosphocholine O-Acyltransferase / Q000378:metabolism; D000818:Animals; D004075:Diglycerides / Q000378:metabolism; D005994:Glycerophosphates / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism*; D008244:Lysophosphatidylcholines / Q000378:metabolism*; D008297:Male; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000378:metabolism*; D008861:Microsomes / Q000648:ultrastructure*; D019301:Oleic Acid; D009829:Oleic Acids; D010713:Phosphatidylcholines / Q000378:metabolism; D010741:Phospholipases A / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D011817:Rabbits; D012128:Respiratory Distress Syndrome / Q000139:chemically induced / Q000378:metabolism*; D014280:Triglycerides / Q000378:metabolism
D004075:Diglycerides; D005994:Glycerophosphates; D008244:Lysophosphatidylcholines; D008563:Membrane Lipids; D009829:Oleic Acids; D010713:Phosphatidylcholines; D010743:Phospholipids; D014280:Triglycerides; D019301:Oleic Acid; C029620:alpha-glycerophosphoric acid; D008243:1-Acylglycerophosphocholine O-Acyltransferase; D010741:Phospholipases A