ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The question of whether magnetic fields affect enzymatic activities or not is of considerable interest in biochemistry and in biomagnetics. Xanthine oxidase, contained in liver, lungs, intestine, and other organs, catalyzes the degradation of hypoxanthine to xanthine, and xanthine to uric acid, which is the terminal waste of purine nucleotides in mammals. During the oxidation of xanthine, the enzyme releases superoxide anion radicals as intermediates which reduce ferricytochrome c (Fe3+). Superoxide anion, as well as any type of free radical, is also paramagnetic. The study is focused on whether these magnetically related enzymatic activities can be affected by magnetic fields. There is a possibility that free radicals, as intermediates, can be modified by magnetic fields of specific intensities. In our previously reported study, we examined a possible effect of magnetic fields up to 1.0 T on biochemical reaction catalyzed by xanthine oxidase, and obtained negative results. In the present abstract, we examine the effect of magnetic fields up to 8 T on this oxidation-reduction process. Reduced cytochrome c (Fe2+) has an absorption maximum at 550 nm which can be detected by a spectrophotometer. Xanthine oxidase was assayed by superoxide dismutase—inhibitable reduction of cytochrome c. We measured optical absorbance of reduced cytochrome c by superoxide anion which was produced by the reaction catalyzed by xanthine oxidase. The absorbances of the mixture exposed to an 8 T magnetic field at 25 °C were higher than control samples in the re-oxidation proces of cytochrome c. The results show that the 8 T magnetic fields altered the rate of reduction of cytochrome c by superoxide anion which was produced by the reaction catalyzed by xanthine oxidase. It may conclude that the electron transfer from xanthine to molecular oxygen or the transfer from superoxide anion to cytochrome c, can be affected by the magnetic fields up to 8 T.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.356688
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