Inflammatory and cardiovascular responses in Experimental Periodontitis, using the bilateral ligation of the first mandibular molar, in Spontaneously Hypertensive Rats (SHR)

Abstract

It is well known that arterial hypertension and the inflammatory process are physiologically related (Rothman et al. 2020). Lately, significant progress has been achieved concerning the understanding of the role of the immune system (innate and adaptive) in the pathophysiology of cardiovascular diseases (Dixon et al., 2020). Taking into account that the experimental model of Periodontitis (bilateral ligation of the first mandibular molar) and the SHR share common inflammatory aspects, but exhibit dissimilar time course; experimental protocols will be carried out under short (10 days) and long term (5 and 10 weeks). After a short period (10 days) it will be examined the role of the activation of both, the baroreflex and the chemoreflex, through the electrical stimulation of the carotid sinus nerve in intact subjects (intact baroreflex and chemoreflex), as well the role of the baroreflex alone, in the subjects with surgical denervation of the chemoreceptors (ligation of the carotid body artery); or, the role of the chemoreflex alone, through the surgical denervation of the carotid baroreceptors, using the methodological approach developed in our laboratory (Katayama et al., 2015). Moreover, after a long period (5 to 10 weeks), it will be examined the role of pharmacological activation of the parasympathetic function using acetylcholinesterase blockers (donepezil and pyridostigmine), administered through Alzet minipumps implanted subcutaneously. Objective: to investigate the role of electrical activation of the baroreceptors and chemoreceptors on the cardiovascular (arterial pressure, heart rate variability, cardiac function and remodeling, and autonomic balance) and inflammatory (bone loss and cytokines) response in the SHR; as well as in their normotensive control counterparts WKY, submitted to the periodontitis elicited by the bilateral ligation of the first mandibular molar. Expected result: discriminate the role of the baroreflex - sympathetic inhibitor and parasympathetic activator, as well as the role of the chemoreflex - simultaneous activator of the sympathetic and parasympathetic, in the cardiovascular and inflammatory responses elicited by Periodontitis in SHR. (AU)