There are two types of nutritionally important polyunsaturated fatty acids (PUFAs),namely ω-6s and ω-3s.PUFAs and their metabolites generated from lipid peroxidation via cyclooxygenase (COX) and lipoxygenase (LOX) are believed to be involved in a variety of physiological and pathological processes in the human body.Both COX- and LOX-catalyzed PUFA peroxidation are complex biochemical events that generate a series of free radicals,which may then bind proteins,target DNA and RNA,and lead to a number of biological changes.However,due to the lack of an appropriate method,it was impossible until recently to identify and quantify the reactive and short-lived PUFA-dedved free radicals in COX/LOX-catalyzed peroxidation.Failure to characterize free radicals during peroxidation has greatly restricted our knowledge about COX/LOX biology and PUFA peroxidation in human health.Here the development and refinement of a technique will be reviewed,which combines spin trapping,liquid chromatography/electron spin resonance (LC/ESR) and liquid chromatography/ mass spectrometry (LC/MS) to characterize PUFA-derived free radicals formed from in vitro (including cellular) peroxidation.The newly refined LC/ESR and LC/MS combination may make it possible for the first time to directly assess the potential bioactivity of PUFA-derived free radicals.This technique has resulted in a major breakthrough in the study of free radicals in biological reactions and will greatly advance and improve the knowledge of PUFAs,COX- and LOX-catalyzed lipid peroxidation,and their related biological consequences.%ω-6和ω-3类多不饱和脂肪酸是两种人体所需的重要营养物质.人体内的很多生理病理过程均涉及到这些多不饱和脂肪酸,以及它们在环氧合酶( cyclooxygenase,COX)和脂氧合酶(lipoxygenase,LOX)催化下产生的过氧化代谢物.环氧合酶和脂氧合酶催化的多不饱和脂肪酸的过氧化是复杂的生化过程,会产生一系列的自由基产物.这些自由基产物又会与蛋白质、DNA和RNA结合,从而导致很多生理功能的改变.然而一直以来,缺乏合适的分析方法来有效分离和鉴定这些自由基产物,限制了人们对环氧合酶和脂氧合晦,以及多不饱和脂肪酸的过氧化在生理作用方面的研究.直到最近,才出现了对COX/LOX催化产生的活泼自由基定性和定量分析的报道.这里将对一种可以用来鉴定体外脂类过氧化产生的自由基产物的自旋捕捉-LC/ESR/MS联用技术的发展与改进过程进行综述.这种新颖的LC/ESR/MS联用技术首次使得直接检测多不饱和脂肪酸代谢产生的自由基成为可能,这对自由基的生理学作用研究是一个重大突破,为人们在多不饱和脂肪酸的生理作用以及环氧合酶和脂氧合酶催化的脂质过氧化方面的研究带来了极大便利.
展开▼
