| Autor: |
BAKKER, HENK D., SCHOLTE, HANS R., VAN DEN, COBY, RUITENBEEK, WIM, JENESON, JEROEN A. L., WANDERS, RONALD J. A., ABELING, NICO G. G. M., DORLAND, BERT, SENGERS, ROB C. A., GENNIP, ALBERT H. VAN |
| Zdroj: |
Pediatric Research (Ovid); January 1993, Vol. 33 Issue: 4 p412-417, 6p |
| Abstrakt: |
In a patient with a mitochondrial myopathy, presenting with lactic acidosis, 31Pnuclear magnetic resonance spectroscopy in resting muscle showed half the creatine phosphate level of controls. The creatine phosphate resynthesis rate after aerobic exercise was only 18 of that in controls. However, the activities of complexes I to V catalyzing oxidative phosphorylation and the pyruvate and the 2oxoglutarate dehydrogenase complexes showed a 2 to 20fold increase. In line with this, the uncoupled mitochondrial respiration rate was significantly higher than in controls. In contrast, the respiration of the mitochondria from the patient was less stimulated by ADP than that of control mitochondria. This finding could point to a defect in complex V, the enzyme directly involved in ATP synthesis. The activity of complex V, measured as the mitochondrial ATPase activity, and its concentration, as judged from Western blots using antisera against the F1part of complex V, were, however, also greatly increased in the patient. Alternatively, the transport system, importing ADP into and exporting ATP out of the mitochondrial matrix, the ADPATP or adenine nucleotide translocator, could be affected. Immunostaining of Western blots revealed a 4fold decrease in the concentration of the adenine nucleotide translocator in the patient. Because oxidative phosphorylation was not disturbed in fibroblasts and lymphocytes, we conclude that this patient suffers from a musclespecific deficiency of his mitochondrial adenine nucleotide translocator, a defect unknown so far. Pediatr Res33 412417, 1993 |
| Databáze: |
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