Srivastava S, Chandra A, Wang L F, Seifert W E, DaGue B B, Ansari N H, Srivastava S K, Bhatnagar A
Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, Galveston, Texas 77555-1067, USA.
J Biol Chem. 1998 May 1;273(18):10893-900. doi: 10.1074/jbc.273.18.10893.
The metabolism of 4-hydroxy-trans-2-nonenal (HNE), an alpha, beta-unsaturated aldehyde generated during lipid peroxidation, was studied in isolated perfused rat hearts. High performance liquid chromatography separation of radioactive metabolites recovered from [3H]HNE-treated hearts revealed four major peaks. Based on the retention times of synthesized standards, peak I, which accounted for 20% radioactivity administered to the heart, was identified to be due to glutathione conjugates of HNE. Peaks II and III, containing 2 and 37% radioactivity, were assigned to 1, 4-dihydroxy-2-nonene (DHN) and 4-hydroxy-2-nonenoic acid, respectively. Peak IV was due to unmetabolized HNE. The electrospray ionization mass spectrum of peak I revealed two prominent metabolites with m/z values corresponding to [M + H]+ of HNE and DHN conjugates with glutathione. The presence of 4-hydroxy-2-nonenoic acid in peak III was substantiated using gas chromatography-chemical ionization mass spectroscopy. When exposed to sorbinil, an inhibitor of aldose reductase, no GS-DHN was recovered in the coronary effluent, and treatment with cyanamide, an inhibitor of aldehyde dehydrogenase, attenuated 4-hydroxy-2-nonenoic acid formation. These results show that the major metabolic transformations of HNE in rat heart involve conjugation with glutathione and oxidation to 4-hydroxy-2-nonenoic acid. Further metabolism of the GS-HNE conjugate involves aldose reductase-mediated reduction, a reaction catalyzed in vitro by homogenous cardiac aldose reductase.
在离体灌注大鼠心脏中研究了脂质过氧化过程中产生的α,β-不饱和醛4-羟基反式-2-壬烯醛（HNE）的代谢。对从[3H]HNE处理的心脏中回收的放射性代谢物进行高效液相色谱分离，显示出四个主要峰。根据合成标准品的保留时间，峰I占给予心脏放射性的20%，被鉴定为HNE的谷胱甘肽共轭物。峰II和峰III分别含有2%和37%的放射性，分别被确定为1,4-二羟基-2-壬烯（DHN）和4-羟基-2-壬烯酸。峰IV是未代谢的HNE。峰I的电喷雾电离质谱显示出两种主要代谢物，其m/z值对应于HNE和DHN与谷胱甘肽共轭物的[M + H]+。使用气相色谱-化学电离质谱证实了峰III中存在4-羟基-2-壬烯酸。当暴露于醛糖还原酶抑制剂索比尼尔时，在冠状动脉流出物中未回收GS-DHN，而用醛脱氢酶抑制剂氰胺处理可减弱4-羟基-2-壬烯酸的形成。这些结果表明，大鼠心脏中HNE的主要代谢转化包括与谷胱甘肽共轭以及氧化为4-羟基-2-壬烯酸。GS-HNE共轭物的进一步代谢涉及醛糖还原酶介导的还原反应，该反应在体外由同质心脏醛糖还原酶催化。
