2.2.1. Antioxidant response in salivary glands of streptozotocin-induced diabetic rats

Diabetes mellitus is a metabolic disorder caused by an insufficiency of secretion or action of endogenous insulin, characterized by hyperglycemia. There is evidence suggesting that the oxidative stress is increased in diabetes mellitus. Objectives: The objectives of the present study was to analyze the influence of diabetes, induced by streptozotocin, on the antioxidant mechanism in submandibular and parotid glands, determining the lipid peroxidation and activity of the enzymes superoxide dismutase, catalase, and glutathione peroxidase on 1, 2, 3 and 4 weeks after the induction. Methods: The enzymes activity was determined by a specific enzymatic system, in spectrophotometer. The lipid peroxidation was determined by the quantification of malondialdehyde. Results: The results showed an increase in the glutathione peroxidase activity and in the content of malondialdehyde in submandibular gland (P<0,05). The parotid gland presented a decrease in the superoxide dismutase activity and high values in the catalase activity and quantification of malondialdehyde (P<0,05). Correlations between glycemia and superoxide dismutase, superoxide dismutase and malondialdehyde, glutathione peroxidase and malondialdehyde was found in parotid gland (P<0,05). Conclusions: There is a lipid peroxidation on parotid and submandibular glands of the studied animals, though the antioxidant enzymatic system in parotid gland is more liable to the hyperglycemic state resulting from experimental diabetes. This study was supported by FAPESP grants 05/03780-0 and 05/04008-0.