Low activities of the pyruvate and oxoglutarate dehydrogenase complexes in five patients with Friedreich's ataxia.
Since patients with Friedreich's ataxia appear to oxidize pyruvate slowly, we measured the activity of the pyruvate dehydrogenase complex in disrupted fibroblasts from four patients with this syndrome and one patient with a clinical variant. The activity was 43 +/- 4 per cent of that in 16 controls (mean +/- S.E.M., P less than 0.001). The activity of the 2-oxoglutarate dehydrogenase complex was also lower in the patients' cells than in those of controls (50 +/- 2 per cent, P less than 0.001). However, the activity of cytochrome-c oxidase was normal (126 +/- 43 per cent of controls). Mixing experiments gave no evidence of soluble enzyme inhibitors or activators, and the addition of excess substrate or cofactor did not ameliorate the deficiencies. White blood cells from one of the patients had low activities of both complexes. Mutations of these dehydrogenase complexes occur in some patients with Friedreich's ataxia and lead to abnormally low activity of an enzyme of the tricarboxylic acid cycle.[1]References
- Low activities of the pyruvate and oxoglutarate dehydrogenase complexes in five patients with Friedreich's ataxia. Blass, J.P., Kark, R.A., Menon, N.K. N. Engl. J. Med. (1976) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg