Role of electrical activation of the carotid sinus nerve in the inflammatory response elicited by colitis

Abstract

Inflammatory bowel diseases, such as Ulcerative Colitis and Crohn's Disease, are characterized by chronic inflammation of the gastrointestinal system. There is no permanent cure; however, neuromodulation induced by electrical nerve stimulation has been used successfully for treatment. However, little is known about baroreflex and chemoreflex activation in the modulation of colitis. Thus, this study aims to evaluate the influence of electrical stimulation of the carotid sinus nerve (CSN), in awake rats, on the inflammatory responses, local and systemic, observed in rats with colitis induced by rectal administration of acetic acid. We will then try to analyze: the hemodynamic parameters; inflammatory cytokines in plasma and the colonic mucosa; structural changes and the expression of NF-ºB in the colon. For this, the rats will receive a catheter in the femoral artery and an electrode in the CSN. After 48 hours, the electrodes will be connected to an electrical stimulator, and blood pressure will be recorded. Subsequently, the rats will be anaesthetized and subjected to colitis induction by administering rectally acetic acid. After 24h, blood will be collected through the cannula in the femoral artery, and the animals will be euthanized to obtain the colon. Part of the colon will be evaluated macroscopically, and microscopically, and the colonic mucosa will also be removed to quantify TNF-±, IL-1², IL-6 and IL-10. Besides, colonic NF-kB expression will be evaluated. Thus, it is postulated in this project that the electrical activation of the CSN may also be an electrometric approach for the treatment of colitis.