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Updated: Sep 8, 2026
Isolation, Culture and Transduction of Adult Mouse Cardiomyocytes
Published on: August 28, 2016
Apoptosis in isolated adult cardiomyocytes exposed to adriamycin
1St. Boniface General Hospital Research Centre, Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
Abstract:
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.
Insights
Adriamycin (doxorubicin) can cause heart failure through cell death. The antioxidant trolox significantly reduced this adriamycin-induced apoptosis and necrosis in rat heart cells.
Area of Science:
- Cardiology
- Toxicology
- Cell Biology
Background:
- Adriamycin (doxorubicin) is a crucial chemotherapy drug.
- Its clinical use is limited by cardiotoxicity, specifically cardiomyopathy and heart failure.
- Oxidative stress is implicated in adriamycin-induced cardiotoxicity.
Purpose of the Study:
- To investigate adriamycin-induced apoptosis in isolated adult rat cardiomyocytes.
- To determine if trolox, a water-soluble antioxidant, can inhibit adriamycin-induced cell death.
Main Methods:
- Isolated adult rat cardiomyocytes were exposed to adriamycin (20 microM for 1 h).
- Cell viability was assessed via cell shape changes, Hoechst 33258 staining, and TUNEL assay.
- DNA fragmentation was analyzed using agarose gel electrophoresis (DNA laddering).
- The effects of trolox treatment were evaluated.
Main Results:
- Adriamycin exposure led to a decrease in rod-shaped cells and an increase in rounded cells.
- Increased myocyte apoptosis and nucleosomal fragmentation were observed.
- DNA laddering and a smear indicating indiscriminate DNA fragmentation (necrosis) were evident.
- Trolox significantly reduced both apoptosis and necrosis.
Conclusions:
- Adriamycin induces cardiomyocyte death through both apoptosis and necrosis.
- Oxidative stress likely mediates these cell death pathways.
- Trolox demonstrates a protective effect against adriamycin-induced cardiotoxicity.
