Role of Superoxide Dismutase in Eustachian Tube of Rat with Acute Otitis Media / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Superoxide dismutase (SOD) is an important protective enzyme against biochemical injury associated with inflammatory reaction. SOD are found in the epithelium of the normal middle ears and lesser amounts are found in infected ears. However, the localization of the SOD in the Eustachian tube in the normal and infected ear has been poorly studied. This study attempted to determine the distribution of SOD and how it changes from normal to infected. MATERIALS AND METHODS:We used fifty male Sprague-Dawley rats to observe the SOD expression and the change of its amount in the Eustachian tube using immunohistochemical method and western blotting. RESULTS: In normal rats, SOD was found in the epithelium of Eustachian tube and lower amounts were found in the connective tissue layers. In the streptococcus-infected ears, SOD was found in the similar pattern, but the infected tubal mucosa showed extensive submucosal edema and stained poorly with SOD, compared to the normal Eustachian tube mucosa. The amounts of SOD was 1.48+/-0.44ng/mg of protein in the normal mucosa and decreased markedly to 0.62+/-0.37ng/mg in the infected cosa. CONCLUSION: SOD was identified in the normal Eustachian tube; the amount decreased during the infected period. This finding suggests that SOD may have a protective role in the pathogenic state.