Parildar Hande, Dogru-Abbasoglu Semra, Mehmetçik Güldal, Ozdemirler Gül, Koçak-Toker Necla, Uysal Müjdat
Department of Biochemistry, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey.
J Nutr Sci Vitaminol (Tokyo). 2008 Feb;54(1):61-5. doi: 10.3177/jnsv.54.61.
The aim of this study was to investigate the effect of the changes of taurine levels in the hearts of old rats on endogenous malondialdehyde (MDA) and diene conjugate (DC) levels and ascorbic acid (AA)- and NADPH-induced lipid peroxidation as well as non-enzymatic (glutathione, vitamin E and vitamin C) and enzymatic antioxidants (superoxide dismutase, glutathione peroxidase and glutathione transferase). Two groups of old (22 mo) rats were treated with beta-alanine (3%, w/v; in drinking water), a taurine depleting agent, or taurine (2% w/v; in drinking water) for 6 wk. Significant decreases were observed in taurine contents of hearts in old rats as compared to young (5 mo) rats. We found that MDA and DC levels and AA- and NADPH-induced lipid peroxidation increased, but non-enzymatic and enzymatic antioxidants did not alter in heart homogenates of aged rats. beta-Alanine administration resulted in significant decreases in heart taurine levels of old rats. This treatment did not cause further increases in MDA or DC levels or changes in antioxidants. However, AA- and NADPH-induced lipid peroxidation was higher than that of old rats. Taurine treatment caused significant increases in heart taurine levels of old rats. This treatment was found to decrease endogenous MDA and DC levels without affecting the antioxidant system in the heart homogenates of aged rats. AA- and NADPH-induced lipid peroxidation was also reduced in old rats when given taurine, although not statistically significantly. Our results indicate that the changes in heart taurine levels may influence the susceptibility of heart tissue to lipid peroxidation in aged rats and that taurine supplementation has protective effects on age-dependent oxidative stress in heart tissue.
本研究旨在探讨老年大鼠心脏中牛磺酸水平变化对内源性丙二醛（MDA）和二烯共轭物（DC）水平、抗坏血酸（AA）和NADPH诱导的脂质过氧化以及非酶（谷胱甘肽、维生素E和维生素C）和酶抗氧化剂（超氧化物歧化酶、谷胱甘肽过氧化物酶和谷胱甘肽转移酶）的影响。两组老年（22月龄）大鼠分别用β-丙氨酸（3%，w/v；溶于饮用水），一种牛磺酸消耗剂，或牛磺酸（2% w/v；溶于饮用水）处理6周。与年轻（5月龄）大鼠相比，老年大鼠心脏中的牛磺酸含量显著降低。我们发现，老年大鼠心脏匀浆中MDA和DC水平以及AA和NADPH诱导的脂质过氧化增加，但非酶和酶抗氧化剂没有改变。给予β-丙氨酸导致老年大鼠心脏牛磺酸水平显著降低。这种处理没有导致MDA或DC水平进一步升高或抗氧化剂变化。然而，AA和NADPH诱导的脂质过氧化高于老年大鼠。牛磺酸处理导致老年大鼠心脏牛磺酸水平显著升高。发现这种处理可降低内源性MDA和DC水平，而不影响老年大鼠心脏匀浆中的抗氧化系统。给予牛磺酸时，老年大鼠中AA和NADPH诱导的脂质过氧化也有所降低，尽管没有统计学显著性。我们的结果表明，心脏牛磺酸水平的变化可能影响老年大鼠心脏组织对脂质过氧化的易感性，并且补充牛磺酸对心脏组织中与年龄相关的氧化应激具有保护作用。
