Age-dependence of free radical-induced oxidative damage in ischemic-reperfused rat heart

Oxygen free radical-induced oxidative damage is involved in both aging and ischemia-reperfusion. The purpose of this study was to determine the aging-induced oxidative alterations in rat heart as well as the age-dependence of heart injury following ischemia-reperfusion. A comparative study was performed on young and old ischemic-reperfused rat hearts. Protein oxidation and the ascorbyl radical level in heart tissue were determined in order to characterize the oxidative stress. Comparing the control conditions, old hearts have 31% more oxidized proteins as measured by protein carbonyl content, and 18% lower ascorbyl radical level as determined by ESR, than young ones. The extent of increase of protein oxidation and ascorbyl free radical depletion induced by ischemia-reperfusion is less pronounced in the old hearts (7 and 8% respectively), as compared to the young ones (55 and 21% respectively). Pre-treatment with a free radical scavenger, such as centrophenoxine, diminished the ischemia-reperfusion injury in both young and old rat hearts.