FATTY-ACID OXIDATION IN FIBROBLASTS FROM PATIENTS WITH DEFECTS IN BETA-OXIDATION AND IN THE RESPIRATORY-CHAIN

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