In Vivo Evidence that Intra-gingivally Administered Porphyromonas gingivalis-derived Lipopolysaccharide Provokes Increases in Blood TNF-alpha Levels of Urethane-anesthetized Rats

The gram-negative bacterium Porphyromonas gingivalis(Pg)is implicated in periodontal disease. Lipopolysaccharide(LPS), a component of the gram-negative bacterial cell wall, contributes to periodontal tissue destruction. The intra-gingival application of Pg-derived LPS(Pg-LPS)increases gingival TNF-alpha without affecting IL-6 in rats. Recognizing periodontal infection's potential threat to health, we investigated the effects of intra-gingival Pg-LPS application on plasma TNF-alpha and IL-6 levels. For comparison, we analyzed the effects of LPS derived from Escherichia coli(Ec-LPS).