Effect of streptozotocin on reactive oxygen species and antioxidant enzyme secretion in rat submandibulary glands: A direct and an indirect relationship between enzyme activation and expression

Abstract

The salivary glands are important exocrine and endocrine organs, whose role in oral health is well recognized.Also these glands contribute to the maintenance of systemic health. During diabetes an impairment of salivaryglands is reported. In this work the oxidative stress produced after 10 days of a single dose of streptozotocinadministration in rats was observed in submandibulary glands. Under this condition a misbalance of theenzymes with antioxidant activity was observed in glands and in incubation medium, as well as in reactiveoxygen species such as hydrogen peroxide (H2O2), superoxide anion (O2•−) and nitric oxide (NO). An increaseof NO and H2O2 and a decrease of O2•− were found. A direct relationship between peroxidase and nitric oxidesynthase (iNOS) activities with enzyme expression was recorded, in contrast an inverse relationship betweensuperoxide dismutase activity and expression was observed. If the high level of H2O2 persists in time as well asa low level of peroxidase, oral pathologies are expected to occur. So, under this situation to study themodulation of enzymes involved in reactive oxygen species metabolism during oxidative stress in oral tissuescould be very important in the managing of oral pathologies.