Experimental studies on the effects of cerebral ischemia and recirculation with respect to free fatty acids and membrane phospholipid molecular species
Goto, Y.
Nihon Geka Hokan. Archiv für Japanische Chirurgie 57(1): 38-54
1988
ISSN/ISBN: 0003-9152 PMID: 3421792 Document Number: 314090
Previous investigators have shown that free fatty acids which accumulated during ischemia are one of indicators of the evolution in ischemic brain damage. This study has sought to delineate the temporal relation after cerebral ischemia and postischemic recirculation between free fatty acid accumulation and degradation of phospholipid molecular species. During ischemia, the cerebral phospholipid molecular species in diacyl phosphatidylcholine (PC) decreased gradually. By contrast, diacyl phosphatidylethanolamine (PE) decreased abruptly after 5 minutes of ischemia. Both diacyl PC and PE showed greater decrease in polyenoic molecular species (especially 16:0-22:6 and 18:0-22:6) than saturated, monoenoic molecular species. Total free fatty acid accumulation was observed according to the time elapsed. Free arachidonic acid and docosahexaenoic acid showed more rapid accumulation than the other fatty acids. At 60 minutes of ischemia, every kind of fatty acid accumulated nonspecifically. In recirculation period, the decrease in phospholipid molecular sepcies content and the increase in free fatty acid have continued as long as 30 minutes. Thereafter, free fatty acid decreased to control values. Reacylation of PC and PE molecular species has not been observed during 120 minutes recirculation period. We have drawn conclusion from this experiment that 1) cerebral ischemia caused differential degradation in each phospholipid classes and preferential hydrolysis in polyenoic molecular species in individual phospholipid class; 2) cerebral recirculation failed to attain reacylation of fatty acid into phospholipid, although the accumulated fatty acid nonpreferentially decreased to control values.