Ultrastructural alterations of the mitochondrial ATPase in the calcium paradox as revealed by negative staining.

We have used a simple negative staining technique to study the structural alterations of mitochondria from biopsies of hearts subjected to the calcium paradox and treatment with diltiazem, a calcium channel blocker. A significant (P less than 0.05) decrease in the number of spheres on the mitochondrial membranes occurs during the calcium paradox (58.0 +/0 4.1/micrometer vs. control 80.5 +/- 6.5). Treatment with diltiazem prevented the loss of spheres from mitochondrial membranes during the calcium paradox (75.5 +20 5.0 micrometer). We found that this negative staining technique can be used for quick assessment of the condition of mitochondria in biopsies from normal and pathological organs.