[Activities of phospholipase A1, A2, lysophospholipase and acylCoA: lysophospholipid acyltransferase in ischemic brain of the dog].
In this report, the sequential changes of phospholipase A1, A2, lysophospholipase and acylCoA: lysophospholipid acyltransferase activities in ischemic dog brain were investigated. The purpose of this study was to examine the enzymic changes of deacylation-reacylation cycle of biomembrane phospholipid in ischemia. Hemispheric non-blood supply models were produced by occlusion of main intracranial trunk arteries in dogs according to Suzuki's method. The sample was spooned out and frozen immediately with liquid nitrogen at the predetermined time. The assay of phospholipase A1, A2 and lysophospholipase activities was done by our method and acylCoA: lysophospholipid acyltransferase activity was according to Corbin and Sun's method. The activities of phospholipase A1, A2 and lysophospholipase did not show significant changes within 60 minutes after arterial occlusion. However these activities showed significant high value at 120 minutes and decreased gradually after then. On the other hand, acylCoA: lysophospholipid acyltransferase activity showed gradual decrease. These findings show that enzymic degradiation of acyl group of phospholipid in the brain is highest at about 120 minutes after complete ischemia. The importance of acyl groups of phospholipids for biomembrane structure and the function is well recognized. The turnover of these acyl groups in normal brain biomembrane is also well known. Some types of enzymic system related to this turnover has been investigated. Phospholipase A1, A2, lysophospholipase and acylCoA: lysophospholipid acyltransferase belong to these enzymic systems. There have been some reports that the content of free fatty acids in the ischemic brain increases in early stage.(ABSTRACT TRUNCATED AT 250 WORDS)
D008243:1-Acylglycerophosphocholine O-Acyltransferase / Q000032:analysis*; D000214:Acyl Coenzyme A / Q000032:analysis*; D000217:Acyltransferases / Q000032:analysis*; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002545:Brain Ischemia / Q000201:enzymology*; D004285:Dogs; D005260:Female; D008245:Lysophospholipase / Q000032:analysis*; D008297:Male; D010740:Phospholipases / Q000032:analysis*; D010741:Phospholipases A / Q000032:analysis*; D054466:Phospholipases A1
D000214:Acyl Coenzyme A; D000217:Acyltransferases; D008243:1-Acylglycerophosphocholine O-Acyltransferase; D010740:Phospholipases; D010741:Phospholipases A; D054466:Phospholipases A1; D008245:Lysophospholipase