Fatty acid oxidation in fibroblasts from patients with defects in β-oxidation and in the respiratory chain

Fatty acid oxidation has been studied with the tritium release assay in cultured fibroblasts from patients with defects in β-oxidation and in the mitochondrial respiratory chain. Cells from all patients with β-oxidation defects and cells from 10 of 16 patients with respiratory chain defects showed an impairment of fatty acid oxidation. The result of the tritium release assay is not only dependent on the proper function of the β-oxidation cycle but is also influenced by the reoxidation of reduced cofactors. The assay can thus be used to study the expression of respiratory chain defects in cultured fibroblasts.