A quantitative analysis of carbon-ion beam-induced reactive oxygen species and redox reactions.

A quantitative analysis of carbon-ion beam-induced reactive oxygen species and redox reactions.
J Clin Biochem Nutr. 2019 Jul;65(1):1-7
Authors: Matsumoto KI, Nyui M, Ueno M, Ogawa Y, Nakanishi I
Abstract
The amounts of reactive oxygen species generated in aqueous samples by irradiation with X-ray or clinical carbon-ion beams were quantified. Hydroxyl radical (•OH), hydrogen peroxide (H2O2), and the total amount of oxidation reactions, which occurred mainly because of •OH and/or hydroperoxy radicals (HO2 •), were measured by electron paramagnetic resonance-based methods. •OH generation was expected to be localized on the track/range of the carbon-ion beam/X-ray, and mM and M levels of •OH generation were observed. Total •OH generation levels were identical at the same dose irrespective of whether X-ray or carbon-ion beam irradiation was used, and were around 0.28-0.35 µmol/L/Gy. However, sparse •OH generation levels decreased with increasing linear energy transfer, and were 0.17, 0.15, and 0.09 µmol/L/Gy for X-ray, 20 keV/µm carbon-ion beam, and >100 keV/µm carbon-ion beam sources, respectively. H2O2 generation was estimated as 0.26, 0.20, and 0.17 µmol/L/Gy, for X-ray, 20 keV/µm carbon-ion beam, and >100 keV/µm carbon-ion beam sources, respectively, whereas the ratios of H2O2 generation per oxygen consumption were 0.63, 0.51, and 3.40, respectively. The amounts of total oxidation reactions were 2.74...

Source: Journal of Clinical Biochemistry and Nutrition - August 7, 2019 Category: Nutrition Tags: J Clin Biochem Nutr Source Type: research