Major pathways of the reno–cardiovascular link: the sympathetic and renin–angiotensin systems

Chronic kidney disease is often characterized by enhanced activity of the renin–angiotensin system (RAS) and the sympathetic nervous system. Independent of their effect on blood pressure, these systems also contribute to the pathogenesis of both structural and functional cardiovascular abnormalities and contribute importantly to clinical outcome. There is much evidence that the diseased kidneys are of central importance in the pathogenesis of both abnormalities. Inhibitors of the RAS also reduce sympathetic overactivity. Future research should be aimed at addressing the pathophysiological mechanisms causing the enhanced activities. Given the fact that even a small kidney lesion can cause enhanced activity of the RAS and the sympathetic nervous system, it is likely that these pathophysiological mechanisms are operational in more disease conditions, including essential hypertension, heart failure, and obesity/metabolic syndrome.