Analysis of mitochondrial XXXX oxidation intermediates by tandem mass spectrometry from intact mitochondria prepared from homogenates of cultured fibroblasts, skeletal muscle cells, and fresh muscle.

@entity1 @entity844 @entity2365 @entity14992 @entity209 @entity121
Defects of mitochondrial @entity844 beta-oxidation are an important group of inherited @entity209 in @entity1 . Despite improved screening opportunities, diagnosis of these disorders is not often straightforward and requires enzyme analyses. Because therapy is effective in many of these disorders, rapid diagnosis is essential. We report a technique that allows analysis of @entity844 oxidation not only in cultured cells (fibroblasts, myoblasts, and myotubes) but also in fresh muscle homogenate. @entity844 oxidation analysis was performed by incubating fresh muscle homogenate or harvested cultured cells with stable isotopically labeled @entity2365 . The intermediates generated were analyzed by tandem mass spectrometry. Results of @entity1 with seven different beta-oxidation disorders were compared with controls. @entity14992 intermediates in @entity1 samples could be easily differentiated from the control samples. The @entity14992 profile of each beta-oxidation defect was compatible with localization of the enzyme defect. Both in @entity1 and control samples, the same pattern of intermediates could be detected in fibroblasts, muscle cells, and fresh muscle homogenate. The procedure described allowed correct diagnosis of all the beta-oxidation defects studied. Utilization of fresh muscle samples reduces the delay in diagnosis related to tissue culture and is useful in diagnostic of @entity1 with neuromuscular phenotype. Measurement of @entity844 oxidation intermediates from myoblasts or myotubes is an additional tool in investigating pathogenetic mechanisms of @entity121 in beta-oxidation defects.
