X-ray microanalysis of calcium, potassium, and phosphorus in liver mitochondria stressed by carbon tetrachloride

Previous measurements of elemental concentrations in liver mitochondria have generally required homogenization and fractionation of liver tissue, a procedure in which it is difficult to rule out ion movement between subcellular units. New techniques involving cryoultramicrotomy of rapidly frozen tissue, high resolution scanning transmission electron microscopy, and X-ray microanalysis were used to measure those elements in rat liver mitochondria reported to have changed following oral administration of carbon tetrachloride (CCl4). Increases in liver mitochondrial calcium were found 24 hr following intoxication by CCl4. Significant early (2 hr) mitochondrial increases in potassium and phosphorus were found following administration of CCl4. The electron microscope technique using quick-frozen samples promises to allow measurement of intracellular ionic concentrations under virtually lifelike conditions.