Studies on the mechanism of vitamin-like activity of coenzyme Q
In: Archives of Biochemistry and Biophysics, Jg. 116 (1966), S. 129-137
Online
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Zugriff:
A vitamin E-deficient diet has been used to produce dystrophy in rabbits. This diet may be considered as an antioxidant-deficient diet because of the lack of structural specificity for vitamin E. Importance is attached to the previous recognition of widespread metabolic damage by such a diet, due to lipid peroxidation, including mitochondrial lipids. Coenzyme Q and its precursors, beginning with 3-decaprenyl-4-hydroxybenzoic acid, are all polyunsaturated lipids and presumably components of mitochondrial membranes. Clearly, coenzyme Q and its precursors are exposed to peroxidation on an antioxidant-deficient diet. Consequently, there may be inadequate levels of coenzyme Q in an animal living on a diet favorable to such peroxidation of lipids. Data supporting low tissue levels of coenzyme Q are yet inconclusive. Hexahydrocoenzyme Q 4 has shown life-saving and vitamin-like activity in the dystrophic rabbit by three criteria: (a) normalization of crcatine-creatinine ratio; (b) regaining of righting reflex; and (c) weight gain. There was no detectable conversion of radioactive 6-chromanol of hexahydrocoenzyme Q 4 to radioactive hexahydrocoenzyme Q 4 or coenzyme Q 10 . Since hexahydrocoenzyme Q 4 , like coenzyme Q 10 , is active for electron transfer in the succinoxidase system, it is evident that the response to hexahydrocoenzyme Q 4 by the rabbit can be due to restored levels of CoQ in the tissue. CoQ 4 substitutes for CoQ 10 and restores the functioning of electron transfer in respiration and coupled oxidative phosphorylation. Since neither the 6-chromanol of hexahydrocoenzyme Q 4 nor α-tocopherol is active for electron transfer in the succinoxidase system, and since there is no apparent conversion of the CoQ-chromanol to the quinone, it is evident that these two chromanols appear to function solely as structurally nonspecific antioxidants which can protect not only tissue levels of CoQ 10 and its precursors but also other body unsaturated lipids against diminution by peroxidation. By such protection, required tissue levels of CoQ 10 could be maintained through intrinsic biosynthesis.
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Studies on the mechanism of vitamin-like activity of coenzyme Q
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Autor/in / Beteiligte Person: | Scholler, Jean ; Moore, Harold W. ; Folkers, Karl ; Smith, Jack L. ; Farley, Thomas M. |
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Zeitschrift: | Archives of Biochemistry and Biophysics, Jg. 116 (1966), S. 129-137 |
Veröffentlichung: | Elsevier BV, 1966 |
Medientyp: | unknown |
ISSN: | 0003-9861 (print) |
DOI: | 10.1016/0003-9861(66)90021-x |
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