ISOZYME-SELECTIVE INDUCTION OF MOUSE PULMONARY SUPEROXIDE-DISMUTASE BY THE EXPOSURE TO MERCURY-VAPOR

Alterations in lung superoxide dismutase (SOD) isozymes after exposure of mice to mercury vapor were examined. Inhalation of mercury vapor ( 10 mg/m(3)) for 1 h by mice resulted in a higher accumulation of mercu ry in the kidney and lung compared to other organs, at 1 h after expos ure. Under these conditions marked enhancement of protein content in b ronchoalveolar fluid (BALF), attributed to lung injury, was observed. Exposure to mercury vapor caused a significant increase in the pulmona ry Cu,Zn-SOD activity (1.32-fold at 48 h) whereas Mn-SOD activity was suppressed to 82% of the control level, suggesting different sensitivi ty to the metal inhalation. The selective induction of Cu,Zn-SOD prote in (1.79-fold at 48 h) was confirmed by immunoblot analysis with polyc lonal antibodies against these isozymes. These observations suggest th at the selective induction of Cu,Zn-SOD at the translational level app ears to occur as an initial defense against mercury-promoted oxidative stress.