Glutathione peroxidase and glutathione transferase activity in rat lung and liver following cadmium inhalation.

A 2-h inhalation exposure to 4.6 mg Cd/m3 decreased pulmonary total glutathione peroxidase (GSH Px) activity and non-selenium peroxidase (GSH non-Se-Px) activity but had no effect on GSH selenium peroxidase (Se-Px) activity. Seventy-two hours after exposure there was an increase in total GSH Px and GSH Se-Px activity and a decrease in GSH non-Se-Px activity. Exposure to 0.44 mg Cd/m3 for 2 h caused no effect on GSH Se-Px at either 0 or 72 h post exposure, but total GSH Px and GSH non-Se-Px activities were decreased up to 72 h post exposure. Exposure to 4.6 mg Cd/m3 caused an increase in hepatic GSH Se-Px activity 72 h post exposure, but no other significant changes were observed in the liver. Changes in GSH non-Se-Px activity did not relate to changes in GSH transferase (Tr) activity. The data suggest that alterations in GSH Px activity by Cd2+ may be due to changes in GSH non-Se-Px activity and that changes in pulmonary GSH Tr and GSH non-Se-Px activities may not be as closely linked as in the liver.