Oral P. gingivalis infection alters the vascular reactivity in healthy and spontaneously atherosclerotic mice

Background: Considering that recent studies have demonstrated endothelial dysfunction in subjects with periodontitis and that there is no information about vascular function in coexistence of periodontitis and atherosclerosis, we assessed the impact of oral inoculation with the periodontal pathogen Porphyromonas gingivalis on vascular reactivity in healthy and hypercholesterolemic apolipoprotein E-deficient (ApoE) mice. In vitro preparations of mesenteric arteriolar bed were used to determine the vascular responses to acetylcholine, sodium nitroprusside and phenylephrine (PE). Results: Alveolar bone resorption, an evidence of periodontitis, was assessed and confirmed in all infected mice. Acetylcholine-and sodium nitroprusside-induced vasorelaxations were similar among all groups. Non-infected ApoE mice were hyperreactive to PE when compared to non-infected healthy mice. P gingivalis infection significantly enhanced the vasoconstriction to PE in both healthy and spontaneous atherosclerotic mice, when compared to their respective controls. Conclusions: This study demonstrates that oral P gingivalis affects the alpha-adrenoceptor-mediated vascular responsiveness in both healthy and spontaneous atherosclerotic mice, reinforcing the association between periodontitis and cardiovascular diseases.