title: Selective inhibition of NADH-CoQ oxidoreductase (complex I) of rat brain mitochondria by arachidonic acid.
abstract: The effects of arachidonic acid on the enzyme complexes in the electron transport system were investigated using submitochondrial particles from rat brain. Arachidonic acid irreversibly inhibited NADH-CoQ oxidoreductase (complex I) activity, but had no effect on the activities of succinate-CoQ oxidoreductase (complex II), CoQH2-cytochrome c oxidoreductase (complex III), cytochrome c oxidase (complex IV), ATPase (complex V), glutamate dehydrogenase, and malate dehydrogenase up to 50 microM. The inhibition was dose-dependent with an IC50 value of 110 nmol/mg protein. The Lineweaver-Burk plot revealed that the inhibition by arachidonic acid was noncompetitive against CoQ with a Ki value of 33 microM and uncompetitive against NADH with a Ki value of 22 microM.
authors.affiliation: Department of Neuroscience, Osaka Bioscience Institute, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Morii
authors.forename: Y
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Y
authors.initials: Y
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology*; D001921:Brain / Q000201:enzymology*; D007700:Kinetics; D008297:Male; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D016660:NAD(P)H Dehydrogenase (Quinone); D010101:Oxygen Consumption / Q000187:drug effects; D011808:Quinone Reductases / Q000037:antagonists & inhibitors*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D001095:Arachidonic Acids; D016718:Arachidonic Acid; D016660:NAD(P)H Dehydrogenase (Quinone); D011808:Quinone Reductases