A model for the oxygen-paradox in mouse cardiac muscle

1. Mouse ventricle strips provide a good model system for studying cellular damage in mammalian cardiac muscle. 2. Anoxia rapidly causes destruction of the myofilament apparatus that is characteristic of calcium-triggered damage in muscle cells, and it is suggested that anoxia promotes release of calcium from the mitochondria. 3. Oxygen exacerbates this damage which is independent of extracellular calcium; it is suggested that it initiates myofilament damage by activation at an intracellular site, probably the sarcoplasmic reticulum.