중이 저류액의 발생기전에서의 활성산소와 항산화계의 역할

Abstract

Reactive Oxygen Species (ROS) are oxygen free radicals and oxygen derivatives that are very unstable and highly chemically reactive due to the presence of a single unpaired electron at the outer most orbit of the oxygen. Despite reports on the significance of ROS and antioxidant enzymes in otitis media, a comprehensive study on the use of total antioxidant status (TAS) in an animal model of otitis media with effusion (OME) has not been reported. Evidence of free radical-induced cellular injury may be gleaned from an assay of by-products, such as malondialdehyde (MDA), as the half-lives of free radicals are extremely brief. In this study, animals were randomly divided into 3 groups: OME (O), Allopruino (A), and control (C). The O group contained Eustchian tube obstruction (ETO) only. The A group contained ETO and intraperitoneal injection of allopurinol. The C group contained unoperated middel ear disease-free animals. The mean level of MDA, activities of xanthine oxidase (XO), catalase (CAT), and TAS were evaluatied by biochemical assays of middle ear mucosa in experimental OME. Expression of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) was evaluated by semiquantiative reverse-transcription polymerase chanin reaction. Effect of allopurinol, an inhibitor of XO, was also evaluated. The valued of MDA, XO, SOD, and GSH-Px exhibited a similar pattern acorss groups, and were highest in O, and lowest in A. The value of GSH-Px in A did not decrease more than C. However, the values of CAT and TAS exhibited a different pattern across groups, and were highest in C, but not significantly different in O and A. These results suggest 1) oxidative stress status (OSS) plays a role in the pathogenesis of OME 2) Allopurinol can reduce ROS production and oxidative tissue damage in OME 3) CAT and TAS may be predisposing factors in the pathogenesis of OME. Further study is needed to determine the molecular mechanism of ROS in OME.