Stabilization of native matrix granules in isolated rat heart mitochondria.

The osmiophilic granules present in the mitochondrial matrix of rat myocardium are very sensitive to changes in the energy status of the cell and in the activity of the mitochondrial electron transport. These granules can be stabilized in isolated mitochondria by blocking the electron transport with Na2S. The behaviour of these native matrix granules is similar to that expected for Ca ++ containing entities.