Mitochondrial three-dimensional form in ascites tumor cells during changes in respiration.

Serial sectioning-reconstruction techniques were used to show the presence of complex, branched mitochondrial forms in Ehrlich-Lettre ascites tumor cells. Although these were the predominant mitochondrial forms present in all cells examined, simple forms, i.e., rods and spheres, also were observed. Attempts to alter the metabolic status of the cell by changing the rate of respiration or degree of coupling of oxidation to phosphorylation did not shift the mitochondrial population from predominantly complex to simple forms. It was shown that complex, branched mitochondrial forms, as well as simple rod and sphere forms were present during coupled, uncoupled, and endogenous respiration and during anaerobiosis. Both complex as well as simple mitochondrial forms underwent transition from an orthodox to a condensed conformation during State 3 respiration. Under the present experimental conditions, differences in mitochondrial forms were not dependent on coupled versus uncoupled respiration or aerobic versus anaerobic state.