Marques Gustavo Lenci, Neto Francisco Filipak, Ribeiro Ciro Alberto de Oliveira, Liebel Samuel, de Fraga Rogério, Bueno Ronaldo da Rocha Loures
Internal Medicine Department - Universidade Federal do Paraná, Brazil.
Cell Biology Department - Universidade Federal do Paraná, Brazil.
Open Cardiovasc Med J. 2015 Oct 30;9:78-82. doi: 10.2174/1874192401509010078. eCollection 2015.
Several theories have been proposed to explain the cause of 'aging'; however, the factors that affect this complex process are still poorly understood. Of these theories, the accumulation of oxidative damage over time is among the most accepted. Particularly, the heart is one of the most affected organs by oxidative stress. The current study, therefore, aimed to investigate oxidative stress markers in myocardial tissue of rats at different ages.
Seventy-two rats were distributed into 6 groups of 12 animals each and maintained for 3, 6, 9, 12, 18 and 24 months. After euthanasia, the heart was removed and the levels of non-protein thiols, lipid peroxidation, and protein carbonylation, as well as superoxide dismutase and catalase activities were determined.
Superoxide dismutase, catalase activity and lipid peroxidation were reduced in the older groups of animals, when compared with the younger group. However, protein carbonylation showed an increase in the 12-month group followed by a decrease in the older groups. In addition, the levels of non-protein thiols were increased in the 12-month group and not detected in the older groups.
Our data showed that oxidative stress is not associated with aging in the heart. However, an increase in non-protein thiols may be an important factor that compensates for the decrease of superoxide dismutase and catalase activity in the oldest rats, to maintain appropriate antioxidant defenses against oxidative insults.
已经提出了几种理论来解释“衰老”的原因；然而，影响这一复杂过程的因素仍未得到充分理解。在这些理论中，随着时间的推移氧化损伤的积累是最被广泛接受的之一。特别是，心脏是受氧化应激影响最严重的器官之一。因此，本研究旨在调查不同年龄大鼠心肌组织中的氧化应激标志物。
将72只大鼠分为6组，每组12只动物，分别饲养3、6、9、12、18和24个月。安乐死后，取出心脏，测定非蛋白巯基、脂质过氧化、蛋白质羰基化水平以及超氧化物歧化酶和过氧化氢酶活性。
与较年轻的组相比，老年组动物的超氧化物歧化酶、过氧化氢酶活性和脂质过氧化水平降低。然而，蛋白质羰基化在12个月组中增加，随后在老年组中降低。此外，非蛋白巯基水平在12个月组中增加，而在老年组中未检测到。
我们的数据表明，氧化应激与心脏衰老无关。然而，非蛋白巯基的增加可能是一个重要因素，它可以补偿最老的大鼠中超氧化物歧化酶和过氧化氢酶活性的降低，以维持对氧化损伤的适当抗氧化防御。
