Laurent A, Perdu-Durand E, Alary J, Debrauwer L, Cravedi J P
Laboratoire des Xénobiotiques, INRA, BP.3, 31931, Toulouse, France.
Toxicol Lett. 2000 Apr 3;114(1-3):203-14. doi: 10.1016/s0378-4274(99)00301-x.
4-Hydroxy-2-nonenal (HNE) is a major aldehydic product of lipid peroxidation known to exert several biological and cytotoxic effects. The in vitro metabolism of [4-(3)H]-HNE by rat precision-cut liver slices was investigated. Liver slices rapidly metabolize HNE - about 85% of 0.1 microM [4-(3)H]-HNE was degraded within 5 min of incubation. The main metabolites of HNE identified were 4-hydroxynonenoic acid (HNA), glutathione-HNE-conjugate (HNE-GSH), glutathione-1,4-dihydroxynonene-conjugate (DHN-GSH) and cysteine-HNE-conjugate (HNE-CYS). Whereas glutathione conjugation demonstrated saturation kinetics (K(m)=412.2+/-152.7 microM and V(max)=12.3+/-2.5 nmol h(-1) per milligram protein), HNA formation was linear up to 500 microM HNE in liver slices. In contrast to previous reports, no trace of the corresponding alcohol of the HNE, 1,4-dihydroxynon-2-ene was detected in the present study. Furthermore, the beta-oxidation of HNA including the formation of tritiated water was demonstrated. The identification of 4-hydroxy-9-carboxy-2-nonenoic acid and 4,9-dihydroxynonanoic acid demonstrated that omega-oxidation significantly contributes to the biotransformation of HNE in liver slices.
4-羟基-2-壬烯醛（HNE）是脂质过氧化的主要醛类产物，已知具有多种生物学和细胞毒性作用。本研究调查了大鼠精密肝切片对[4-(³H)]-HNE的体外代谢情况。肝切片能迅速代谢HNE——在孵育5分钟内，0.1微摩尔[4-(³H)]-HNE中约85%被降解。鉴定出的HNE主要代谢产物有4-羟基壬烯酸（HNA）、谷胱甘肽-HNE缀合物（HNE-GSH）、谷胱甘肽-1,4-二羟基壬烯缀合物（DHN-GSH）和半胱氨酸-HNE缀合物（HNE-CYS）。谷胱甘肽结合表现出饱和动力学（米氏常数K(m)=412.2±152.7微摩尔，最大反应速度V(max)=12.3±2.5纳摩尔每小时每毫克蛋白质），而在肝切片中，高达500微摩尔HNE时HNA的形成呈线性。与之前的报道不同，本研究未检测到HNE相应醇类1,4-二羟基壬-2-烯的踪迹。此外，还证实了HNA的β-氧化，包括氚化水的形成。4-羟基-9-羧基-2-壬烯酸和4,9-二羟基壬酸的鉴定表明，ω-氧化对肝切片中HNE的生物转化有显著贡献。
