Abstract
A 16-years old girl has progressive loss of muscular strength, on exertion muscle pains, lactic acidosis and ketosis. Load tests with glucose, fructose, alanine, and lactate show normal metabolism at rest. Lactate accumulation is only dependent on muscular activity. Investigation of an open muscle biopsy showed normal glycogen content and normal activities of glycogenolytic enzymes (Dr. Schaub, Munich) and mild mitochondrial abnormalities on electron microscopy (Prof. Peiffer, Prof. Schlote, Tübingen). Muscle mitochondria were studied by O2 polarography and spectroscopy according to Brauser, 1968: respiration rate with succinate was normal, it was decreased with NADH linked substrates (malate/glutamate and malate/pyruvate 10 % of normal). Contents of cyt were normal. The percentage of cyt b reduced was minimal, while that of cyt c was increased. Reduction of cyt b occurred only after antimycin. Therapeutic trials with riboflavin, succinate, and long-chain fatty acids have been without effect. Possible explanations for these findings are: 1) increased negativity of the cyt b potential with normal flow of electrons and 2) direct flow of electrons from succinate dehydrogenase to cyt c.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Przyrembel, H., Brauser, B. & Bremer, H. Myopathy with lactic acidosis and altered redox state of the respiratory chain cytochromes (cyt). Pediatr Res 13, 73 (1979). https://doi.org/10.1203/00006450-197901000-00025
Issue Date:
DOI: https://doi.org/10.1203/00006450-197901000-00025