Doxycycline May Block Progressive Bone Loss in Hypertensive Rats

Method: Using a ligature-induced periodontitis model, 40 Spontaneously Hypertensive Rats (SHR) were assigned to one of the following groups: SHR-C, SHR-PD, SHR-C-DOX and SHR-PD-DOX (C – control group, PD – periodontitis group, DOX- Doxycycline groups). On DOX groups, all animals received doxycycline (5mg/Kg), daily by oral gavage. On PD groups, the first mandibular molar received a cotton ligature at baseline. After 10 days, 5 animals of each group were sacrificed and the ligatures of the other animals were removed. On the 21^th day (11 days without ligatures), the remaining animals were sacrificed. The jaws were resected and the distances between the alveolar bone crests and the cement-enamel junctions (ABC-CEJ, mm) were morphometrically analyzed. The obtained data were subjected to statistical analysis by ANOVA (p<0.05).

Result: After 10 days, the PD groups showed more bone loss (p<0.05) than the controls (SHR-PD= 0.72±0.05; SHR-C= 0.39±0.04; SHR-PD-DOX= 0.68±0.02; SHR-C-DOX= 0.49±0.03). At 21 days, while SHR-PD group (0.95±0.13) showed a progressive bone loss (p<0.05), none of the DOX groups (SHR-PD-DOX= 0.71±0.03; SHR-C-DOX= 0.51±0.05) presented alveolar bone loss progression (p>0.05).

Conclusion: Therefore, it may be concluded that the host response modulation by Doxycycline may reduce PD progression after ligature removal in hypertensive rats.