Modulation of SOD activity in rat submandibular glands

Reactive oxygen species (ROS) such as superoxide anion (O2−), hydrogen peroxide (H2O2) and hydroxyl radical (OH) are produced constantly in aerobic organisms. Submandibular glands of rats treated with isoproterenol (ISO) were analysed in respect to the level of superoxide dismutase (SOD), lipoperoxidation, protein oxidation and glutathione (GSH)/GSSG. Although ISO response is very well studied in salivary glands cells, the effect of ISO treatment on ROS productions or on SOD activation is not known. SOD activity increased after isoproterenol subcutaneous injection. In contrast, cycloheximide, a protein synthesis inhibitor, was found to decrease the total SOD activity. The GSH/GSSG ratio and the lipoperoxidation were also found to be increased after isoproterenol injection, while the protein oxidation was not affected by the same treatment. Injection of isoproterenol after cycloheximide treatment resulted in the recovery of the total SOD activity. This increase of activity is related to the amount of MnSOD isoform as shown by Western blot analysis. Our results suggest that the antioxidant protection of SOD may be activated during the salivary glands ISO treatment and that the mitochondrial MnSOD has an important role in the oxidative stress process.