Background: The present study was designed to examine whether the intermittent local periodontal inflammation induces endothelial dysfunction of the systemic artery caused by oxidative stress and if increased levels of hydrogen peroxide coexisted with overexpression of superoxide dismutase (SOD) as well as NADPH oxidase contribute to the oxidative stress.
Methods: The rats in lipopolysaccharides (LPS) group received 1500μg LPS injection to bilateral gingiva of the lower jaw a week interval from eight- to eleven-week-old. Isolated mandibles or aortas were subjected to the evaluation of histopathological changes, isometric force recordings, reactive oxygen species using 2',7'-dichlorofluorescin diacetate (10(-5)mol/L) and protein expression of NADPH oxidase subunits and SOD, respectively.
Results: Mandible sections demonstrated the periodontal inflammation only in the LPS group at three days, but not seven days, after the LSP injection. Acetylcholine (10(-9) to 10(-5)mol/L)-induced relaxation was reduced only in aortas from the LPS group. Gp91ds-tat and PEG-catalase restored the impaired dilation in arteries from the LPS group. Levels of reactive oxygen species were enhanced in aortas from the LPS group, whereas the increment was abolished by the treatment with gp91-ds-tat or PEG-catalase. Expression of a NADPH oxidase subunit p47phox and CuZn-SOD increased in the LPS group.
Conclusions: The intermittent local periodontal inflammation induces systemic endothelial dysfunction caused by overproduction of reactive oxygen species in the systemic artery of rats and that overexpression of CuZn-SOD as well as a NADPH oxidase cytosolic subunit contributes to increased levels of hydrogen peroxide in blood vessels of this animal model.
Keywords: Artery; Endothelial function; Hydrogen peroxide; Intermittent periodontal inflammation; NADPH oxidase.
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