Flow cytometric evaluation of defects of the mitochondrial respiratory chain

Abstract

Cultured human skin fibroblasts from 12 patients with a variety of mitochondrial respiratory chain defects were examined for their capacity to oxidize dihydrorhodamine-123 to the fluorescent molecule rhodamine-123 using a flow cytometer. We found that cells from patients with functional defects in respiratory chain enzymes were less able to oxidize dihydrorhodamine-123 than those of healthy controls. Ten of the cell strains had reduced activity in at least one of the respiratory chain complexes and also showed significantly reduced fluorescence when compared to the mean of eight normal control cell strains. One patient had mitochondrial encephalomyopathy, lactic acidosis, and strokelike epis..