ABSTRACT
Reactive oxygen species (ROS) such as superoxide anion (O(2)(*-)), hydrogen peroxide (H(2)O(2)) 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.
Subject(s)
Adrenergic beta-Agonists/pharmacology , Cycloheximide/pharmacology , Isoproterenol/pharmacology , Protein Synthesis Inhibitors/pharmacology , Submandibular Gland/drug effects , Superoxide Dismutase/metabolism , Animals , Blotting, Western/methods , Glutathione/metabolism , Lipid Peroxidation , Male , Rats , Rats, Wistar , Submandibular Gland/enzymologyABSTRACT
As espécies reativas de oxigênio geradas in vivo têm sido implicadas em vários mecanismos como apoptose, crescimento e diferenciação celular, câncer e inflamação. O estresse oxidativo é o produto do desbalanço entre os agentes pro-oxidantes e antioxidantes celulares, causando danos por meio da peroxidação lipídica, oxidação de proteínas e de DNA. Neste trabalho, avaliou-se o efeito do estresse oxidativo em glândulas submandibulares de rato e em células acinares dispersas tratadas com isoproterenol (ISO), cicloheximida (CHX), carbacol (CA) e propanolol (PROP). Observou-se aumento dos níveis de MDA em homogenados de glândulas de ratos tratados com ISO e CHX e em células acinares dispersas incubadas com ISO e CHX...