Baroreflex and Adaptation of Visceral Systems in Renovascular Hypertension

Objective. To test the hypothesis, that the arterial baroreceptor refl ex plays the key role for the phenomenon of visceral systems adaptation for long-term afferent drive. Design and methods. In Wistar rats the model of the «two kidneys, one clip» vasorenal hypertension was carried out. The sino-aortic denervation was performed in one group — before the left renal artery clipping, in the other group — 8 weeks after the left renal artery clipping. Results. The renal artery clipping led to the increase of blood pressure only in 17 % of animals with intact sino-carotid-aortic mechanoreceptor zones. The absence of hypertension in these animals might be due to the cardiovascular adaptation phenomenon to prolonged afferent action from ischemic kidney. Denervation of mechanoreceptor zones before the clipping of the renal artery contributes to the development of hypertension in 100 %. However, the denervation of sino-carotid and aortic zones performed 8 weeks after the renal artery clipping in rats without hypertension, does not affect blood pressure level. Conclusion. We suggest, that the absence of hypertension after renal artery clipping is due to the adaptation of the circulatory system to a long-term afferentation from the kidney, and the denervation of large vessels mechanoreceptor zones does not alter this process. At the same time, the damage of the arterial baroreceptor refl ex before renal artery clipping interferes in the visceral systems adaptation to afferent action and contributes to the arterial hypertension development.