Prasad M R, Das D K
Department of Surgery, University of Connecticut School of Medicine, Farmington 06032.
Free Radic Res Commun. 1989;7(3-6):381-8. doi: 10.3109/10715768909087965.
The abilities of chemically generated hydroxyl radical (OH.), superoxide anion (O.-) and hydrogen peroxide (H2O2) to degrade rat myocardial membrane phospholipids previously labeled with [1-14C]arachidonic acid were studied. HO. and H2O2, but not O2.-, caused the degradation of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylinositol (PI). With OH. and H2O2, the loss of radiolabel in PC was accompanied by an increase in the radiolabel of lysophosphatidylcholine (LPC), but not in that of free fatty acid (FFA). These results suggest the hydrolysis of 1-oxygen ester bond of PC by HO. and that H2O2 and that HO. and H2O2, but not O.-, are detrimental to the structure and function of membrane phospholipids. However, since microM amounts of HO. and mM amounts of H2O2 were necessary to affect the membrane phospholipids, it is likely that in the reperfused myocardium only HO., but not H2O2, may directly cause the breakdown of membrane phospholipids.
研究了化学产生的羟基自由基（OH·）、超氧阴离子（O₂⁻）和过氧化氢（H₂O₂）降解先前用[1-¹⁴C]花生四烯酸标记的大鼠心肌膜磷脂的能力。OH·和H₂O₂能导致磷脂酰胆碱（PC）、磷脂酰乙醇胺（PE）和磷脂酰肌醇（PI）的降解，而O₂⁻则不能。在OH·和H₂O₂作用下，PC中放射性标记物的损失伴随着溶血磷脂酰胆碱（LPC）放射性标记物的增加，但游离脂肪酸（FFA）的放射性标记物没有增加。这些结果表明OH·可水解PC的1-氧酯键，H₂O₂也可，且OH·和H₂O₂（而非O₂⁻）对膜磷脂的结构和功能有害。然而，由于影响膜磷脂需要微摩尔量的OH·和毫摩尔量的H₂O₂，因此在再灌注心肌中，可能只有OH·而非H₂O₂会直接导致膜磷脂的分解。
