title: Two cases of NADH-coenzyme Q reductase deficiency: relationship to MELAS syndrome.
abstract: Muscle biopsy specimens from two patients with MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes) were studied biochemically. 14CO2 production rates from (1-14C)pyruvate, (U-14C)malate, and (1-14C)2-ketoglutarate were all decreased in intact mitochondria in both patients. Rotenone-sensitive NADH cytochrome c reductase activities were decreased to 8% (patient 1) and 6% (patient 2) of control values; succinate cytochrome c reductase and cytochrome c oxidase values were within normal limits. These results indicate that both patients have a defect of NADH-CoQ reductase of the respiratory chain and that MELAS can be brought about by a defect of NADH-CoQ reductase.
mesh_terms: D000140:Acidosis, Lactic / Q000201:enzymology*; D000293:Adolescent; D001927:Brain Diseases / Q000201:enzymology*; D002561:Cerebrovascular Disorders / Q000201:enzymology*; D006801:Humans; D008297:Male; D008931:Mitochondria, Muscle / Q000378:metabolism; D009135:Muscular Diseases / Q000201:enzymology*; D009243:NAD / Q000172:deficiency*; D016660:NAD(P)H Dehydrogenase (Quinone); D011808:Quinone Reductases / Q000172:deficiency*; D013577:Syndrome
chemical_list: D009243:NAD; D016660:NAD(P)H Dehydrogenase (Quinone); D011808:Quinone Reductases