REOXYGENATION-INDUCED CELL-DAMAGE OF ISOLATED NEONATAL RAT VENTRICULAR MYOCYTES CAN BE REDUCED BY CHAIN-BREAKING ANTIOXIDANTS

To study the role of chain-breaking antioxidants on reperfusion injury in the ischemic heart, cultured ventricular heart cells (myocytes) we re subjected to hypoxia and reoxygenation. The myocytes were prepared from neonatal rats and cultured in F10 medium that was supplemented wi th serum. As a marker for cell damage, lactate dehydrogenase was analy zed in the medium. Cells subjected to hypoxia for 5 h showed a 1.9 fol d increase in lactate dehydrogenase (LD) leakage, while cells subjecte d to 1 h hypoxia followed by 4 h reoxygenation showed a 5-fold increas e in LD leakage. Alpha-tocopherol, beta-carotene, nordihydroguairetic acid (NDGA), butylated hydroxyltoluene (BHT), and ICI 211965 were adde d to the cell medium every 24 h for 6 d prior to reoxygenation. All co mpounds protected against reoxygenation-induced cell damage. In the pr esence of the 5-lipoxygenase inhibit or ICI 211965, protection against LD leakage was found only at high concentrations, which corresponded to the antioxidative effect of ICI 211965, and not to inhibition of 5- lipoxygenase. We conclude that cultured ventricular myocytes can be us ed to evaluate the protective effect of antioxidants on reoxygenation- induced cell damage, and that chain-breaking antioxidants protected we ll against reoxygenation-induced cell damage.