Adriamycin exposure in isolated adult rat cardiomyocytes induced both apoptosis and necrosis, which were significantly reduced by the antioxidant trolox.
Does trolox inhibit adriamycin-induced apoptosis and necrosis in isolated adult rat cardiomyocytes?
Adriamycin-induced cell death in cardiomyocytes involves both apoptosis and necrosis mediated by oxidative stress, which can be attenuated by the antioxidant trolox.
Adriamycin (doxorubicin) is a highly potent antineoplastic agent, but its use is limited by the risk of developing cardiomyopathy and congestive heart failure. Available evidence suggests that adriamycin-induced congestive heart failure is mediated by oxidative stress. We examined the possibility of adriamycin-induced apoptosis in isolated adult rat cardiomyocytes and its inhibition by trolox, a water-soluble antioxidant. Cardiomyocytes isolated from rat hearts were exposed to 20 microM adriamycin for 1 h and examined at different post-treatment durations (0-23 h). Adriamycin caused a significant decrease in rod-shaped cells and an increase in round cells. Both Hoechst 33258 staining and TUNEL assay revealed a significantly increased number of apoptotic myocytes and nucleosomal fragmentation upon exposure to adriamycin. In agarose gel electrophoresis, DNA laddering was found to be more intense in adriamycin-exposed myocytes. A bright smear at the leading edge of the gels suggested indiscriminate fragmentation of DNA and myocyte necrosis by adriamycin. Both types of DNA degradations due to adriamycin were significantly reduced by trolox. We suggest that adriamycin-induced cell death involves both apoptosis and necrosis and these may be mediated by oxidative stress.
Kumar et al. (Tue,) conducted a other in Adriamycin-induced cardiomyopathy. Adriamycin and Trolox vs. Unexposed / Adriamycin without Trolox was evaluated on Apoptosis and necrosis (cell shape changes, DNA fragmentation). Adriamycin exposure in isolated adult rat cardiomyocytes induced both apoptosis and necrosis, which were significantly reduced by the antioxidant trolox.