X-RAY MICROANALYSIS OF CALCIUM IN ISCHEMIC SKELETAL MUSCLE CELLS

Tissue sections of both transiently and persistently ischemic musculus latissimus dorsi of rabbitsshow degenerated and necrotic cells in varying degrees. Degenerated mitochondria appearing in the cellscontain moderate electron-dense fluffy intramatrical deposits. However, only in the transient ischemia sam-ple can other two kinds of electron-dense granules be seen between myofibrils. According to their ultra-structure, size and distribution, the larger granules are considered the degenerated mitochondria, and thesmaller ones the degenerated sarcoplasmic reticulum. X-ray microanalysis proves that these two kinds ofgranules contain high concentration of calcium, while the fluffy deposits contain little calcium. The find-ings suggest that the calcium deposits in the degenerated and necrotic cell seen under light microscopeoccur in mitochondria and sarcoplasmic reticulum of the transiently ischemic muscle cell. The conditionsof calcium accumulation in ischemic muscle cells are discussed.