Figure 2. Intravital microscopy analysis of early-phase vascular permeability increases elicited by topically applied P. gingivalis.

(A) Upper panel: Diameter changes (means ± SEM) in arterioles in two groups of HCP (n=5) topically exposed to W83 P. gingivalis. Control experiments were performed by adding HOE-140 to one group of hamsters. Note that there was a significant smaller diameter increase as compared with the untreated control group at 10 and 15 minutes after bacteria application, * = p < 0.05. (A), Lower Panel. The graph describes plasma leakage (FITC-dextran) responses (means ± SEM) for two groups of hamsters. After local application of HOE-140 to one group (see second bacteria application) there was significantly less plasma leakage at 10, 15 and 20 min as compared with the untreated control group, * = p < 0.05. (B) Upper Panel. Diameter changes (means ± SEM) in hamster cheek pouch arterioles in one group of hamsters (n = 5) receiving bacteria applications with 40 min interval. The first application was made with the P.gingivalis W83 (Bact 1) pretreated in vitro with Rgps inhibitor. There was only a significant difference (p < 0.05) in arteriolar diameter at 10 min after application of W83 P. gingivalis (Bact 1) + inhibitor as compared with 10 min after application of W83 without Rgps inhibitor (Bact 2). Lower Panel. Vascular permeability changes (means ± SEM) recorded in two groups of hamsters. There were significant differences in plasma leakage (Fluorescence) induced by the first and the second application of bacteria at 10, 15, 20, 25 and 30 min (* = p < 0.05). Plasma leakage increase after application of W83 (Bact 1) + Rgps inhibitor was 64 % of the control response induced by the untreated W83 (Bact 2). Statistical evaluation was made by a paired t-test comparing the responses of first bacteria application with those of the second.