Sympathoexcitation and autonomic dysfunction contribute to both the development and maintenance of renovascular hypertension. The reninangiotensin-aldosterone-system(RAAS) has a major role in the autonomicdisorder seen in 2 kidneys-1clip (2K1C), an animal model of renovascular hypertension. The actions of angiotensin II (Ang II) and aldosterone (Aldo) in the baroreflex dysfunction in 2K1C model have already been studied, but the relative role of Ang II and Aldo on chemoreflex function, in this model, remains unclear. It is known that peripheral chemoreceptor denervation reduces arterialpressure (AP), improves renal function and increases baroreflex gain in 2K1Cmodel. However, the interaction between the kidneys and the carotid body on the autonomic control in 2K1C is not well understood. The aim of this project will be evaluate the cross talk between kidneys and carotid body on autonomicdysfunction in 2K1C model as well as the role of RAAS in this cross talk. To test our hypothesis, we intend to evaluate, via radio telemetry devices, the effects of carotid bodies denervation on AP, sympathetic nerve activity (SNA), baroreceptor reflex function and renal function in conscious sham operated and 2K1C rats. After that, the activity of carotid body afferents using whole nerverecording from the carotid sinus nerve and single cell recordings from the petrosal ganglion using the in situ working heart brainstem preparation in sham operated and 2K1C animals will be evaluated. Finally, using the in situ preparation, we will focally apply on carotid body AT1 and MR receptors antagonists to evaluate the role of RAAS in the carotid body and measure changes in AP, SNA and baroreflex function will evaluated in sham operated and 2K1C rats.
News published in Agência FAPESP Newsletter about the scholarship: