DETECTION AND REGULATION OF CU ZN-SOD AND MN-SOD IN RAT COCHLEAR TISSUES/

Relative levels of copper/zinc-superoxide dismutase (Cu/Zn-SOD) and ma nganese-superoxide dismutase (Mn-SOD) in individual cochlear tissues w ere detected by the use of an enzyme-linked immunosorbent assay (ELISA ). A heterogeneous distribution of Cu/Zn-SOD was observed in the indiv idual tissues of control animals: high levels were measured in the str ia vascularis (SV), intermediate levels of enzyme were measured in the spiral ligament (SL), and low levels were measured in the organ of Co rti region (OC); collectively, these levels were not statistically sig nificant (P = 0.0645). Levels of Mn-SOD in individual tissues of the c ontrol group were statistically significant (P < 0.05): high levels we re measured in the SV, medium levels were detected in the SL, and low levels were identified in the OC. Following the administration of meth ylprednisolone (MP), a significant reduction of Cu/Zn-SOD in the SV (P < 0.05) and a non-significant, but noticeable, increase (> 30%) of Mn -SOD in the OC were observed. These results indicate that levels of SO D are tissue specific and that SOD is subject to glucocorticoid regula tion.