Expressions of Interleukin-1β and Interleukin-6 Within Aortas and Uteri of Rats with Various Severities of Ligature-Induced Periodontitis

To investigate the associations of periodontitis with histological lesions in some other organs, various severities of periodontitis were induced in rats by 3/0 silk ligatures tied around different numbers of their molar necks. Six weeks after the initial placement of ligatures, all rats were sacrificed by an anaesthetic overdose. The distances from the cemento-enamel junction to the alveolar bone crest within the placement zone of the ligature and their contralateral zone in groups L₂ and L₃ were measured. The levels of interleukin (IL)-1β and IL-6 in serum were assayed by enzyme-linked immunosorbent assay techniques, and those within aortas and uteri were measured by real-time polymerase chain reaction and by immunohistochemistry. We divided the ligature-induced periodontitis models into mild, moderate and severe rat periodontitis and observed that although no association between periodontitis and the serum concentrations of IL-1β was detected, the differences in the severity of rat periodontitis led to varying degrees of elevated expressions of IL-1β and IL-6 within aortas and uteri.