Relationship between tissue hydroxyl radical and oxidatively modified macromolecule levels.

AimsThe relationship between hydroxyl radical (OH) and oxidatively modified macromolecule formations was examined in tissues from young and aged mice. MethodsTo determine the OH generation in tissues invivo using the hydroxylation trapping reaction of OH into salicylic acid (SA), analytical conditions for dihydroxybenzoic acid (DHBA) and SA determination, and optimum dosages of SA for administration and time-points of tissue sampling were determined. 2, 3-DHBA levels in tissues from young mice and age-related changes were determined with the oxidatively modified macromolecules. Results2, 3-DHBA, a hydroxylation compound of SA, is considered to be suitable for determination of OH levels in tissues. Tissue levels of 2, 3-DHBA expressed as a molar ratio to SA, was comparable among tissues, and was in accordance with 8-oxo-2-deoxyguanosine (8-oxodG) and carbonylated proteins. In the aging process, 2, 3-DHBA levels in the brain and heart increased in the biphasic pattern in accordance with the 8-oxodG and thiobarbituric acid reactive substances (TBARS) levels, whereas levels of carbonylated proteins were not changed with age. ConclusionsAn invivo method for OH measurement using hydroxylation of SA was optimized. However, as a limitation, 2, 3-DHBA, as well as other oxidative stress markers, could be affected by various invivo factors. The accordance was seen among 2, 3-DHBA, 8-oxodG and carbonylated protein levels in tissues from young mice. The tissue levels of 2, 3-DHBA increased in accordance with the 8-oxodG and TBARS during the aging process. Geriatr Gerontol Int 2014; 14: 498-507.