Zambonin Laura, Prata Cecilia, Cabrini Luciana, Maraldi Tullia, Fiorentini Diana, Vieceli Dalla Sega Francesco, Hakim Gabriele, Landi Laura
Dipartimento di Biochimica, Alma Mater Studiorum Università di Bologna, Via Irnerio 48, 40126 Bologna, Italy.
Free Radic Biol Med. 2008 Feb 15;44(4):594-601. doi: 10.1016/j.freeradbiomed.2007.10.034. Epub 2007 Oct 22.
In a previous paper, we demonstrated that tissue trans fatty acids can not only derive from the diet but also be endogenously formed. The central focus of this study was to prove that the in vivo isomerization occurs via a radical process. Two different models of radical insult were used: CCl(4) and AAPH injection to rats fed a diet completely free of trans isomers. Following this acute radical stress, a significant increase in unnatural trans fatty acid content of erythrocyte, kidney, and heart, but not liver, was observed. These results can be mainly explained by the high content, particularly in the liver, of antioxidant vitamins A and E that exhibit also an "anti-isomerizing" effect. Since during ageing cellular components are exposed to increasing radical insults, the observation of a significant trans fatty acid accumulation in 30-month-old rats could confirm that the in vivo formation of unnatural isomers is due to a radical process. Trans fatty acids can influence the physical characteristics of bilayer microdomains, affecting membrane properties and functions; thus, knowledge of biological radical species responsible for cis/trans isomerization and their possible sources can provide protective systems for preserving lipid geometry.
在之前的一篇论文中，我们证明了组织反式脂肪酸不仅可以来源于饮食，还可以内源性形成。本研究的核心重点是证明体内异构化是通过自由基过程发生的。我们使用了两种不同的自由基损伤模型：向完全不含反式异构体的饮食喂养的大鼠注射四氯化碳（CCl₄）和偶氮二异丁脒盐酸盐（AAPH）。在这种急性自由基应激之后，观察到红细胞、肾脏和心脏（而非肝脏）中不自然的反式脂肪酸含量显著增加。这些结果主要可以通过抗氧化维生素A和E的高含量来解释，尤其是在肝脏中，它们还表现出“抗异构化”作用。由于在衰老过程中细胞成分会受到越来越多的自由基损伤，在30月龄大鼠中观察到显著的反式脂肪酸积累可以证实，体内不自然异构体的形成是由于自由基过程。反式脂肪酸可以影响双层微区的物理特性，影响膜的性质和功能；因此，了解负责顺式/反式异构化的生物自由基种类及其可能来源，可以为保护脂质几何结构提供保护系统。
