Abstract P285: Carotid Sinus Nerve Stimulation Attenuates Alveolar Bone Loss in Rats With Induced Periodontitis.

Abstract

Introduction: Few studies have focused on the impact of the progression of periodontitis on hypertension. Baroreflex Activation Therapy (BAT) has been used to treat patients with resistant hypertension. Our laboratory has investigated the role of electrical carotid sinus nerve (CSN) stimulation in unanesthetized rats, on local and systemic inflammation. Since periodontitis is a chronic inflammatory disease, the aim of this study was to evaluate the role of the baro- and chemoreflex activation, by means of electrical stimulation of the CSN, on alveolar bone loss in rats with periodontitis. Methods and Results: Under ketamine/xylazine anesthesia Wistar Hannover rats were implanted with electrodes around the CSN and a catheter inserted into the abdominal aorta for blood pressure recording. After 48h periodontitis was induced by the ligation of the bilateral mandibular first molar, followed by the electrical stimulation of the CSN (1,5-4V, 1ms, 30Hz for 10 min); which was continued during the next eight days. At the 8 th day after the induction of periodontitis, the rats were euthanized and the jaws were resected; besides, microtomographic analysis was performed by bi and three-dimensional quantification using micro-computerized tomography. As compared to baseline results the electrical stimulation of the CSN (N=7) promoted a decrease in mean arterial pressure (108± 8 vs. 91± 5 mmHg; p<0.05) and heart rate (374±10 vs. 319±15 bpm; p<0.05). The CSN stimulated rats (N=7) with periodontitis showed greater bone volume and bone surface than the non-stimulated control rats (N=4) with periodontitis, evaluated by three-dimensional analysis (0.5±0.005 vs. 0.7±0.03 mm 3 ; 16.54±0.22 vs. 23.30±0.66 mm 2 , respectively; p<0.05). Moreover, the CSN stimulated rats with periodontitis presented a decrease of the furcation area and interproximal region as compared to the non-stimulated control rats (1.14±0.06 vs. 0.5±0.07 mm; 3.25±0.03 vs. 2,48±0,13 mm, respectively; p<0.05). Conclusions: Overall, these results demonstrate that stimulation of the CSNs promotes a protective effect on alveolar bone loss elicited by periodontitis involving the activation of the baro- and chemoreflex.