Quantitative electron microscopic study of calcium accumulation in cerebral ischemia mitochondria.

Formation of calcium deposits in mitochondria is a consistent feature of irreversible injury in ischemic myocardium. We studied calcium accumulation in nerve cell mitochondria in a cat model 30 and 60 minutes after cerebral ischemia localized in the anterior part of the caudate nucleus and adjacent internal capsule. In control animals, calcium deposits were visible in synaptic vesicles, Golgi apparatus, mitochondria, lysosomes, and in glial and neuronal nuclei. After cerebral ischemia, findings included astrocytic swelling and degeneration of neurons, with an increase in calcium pyroantimoniate mitochondrial deposits. Content of intramitochondrial calcium deposits is related to duration of ischemia as well as the amount of cellular lesions.