Pathophysiology of cardiorenal interaction

In the renal circulation, the afferent arterioles leading to juxtamedullary glomeruli are anatomically under high pressure load in order to reduce the high arterial pressure and keep the pressure of the following glomeruli at about 50 mmHg. Because of the pressure overload, it is possible that vascular injury begins in the afferent arterioles of juxtamedullary glomeruli. We call such high pressure-loaded vessels branching directly from relatively large vessels 'strain vessels'. Coronary arteries and penetrating cerebral arteries are also strain vessels. They are also susceptible to pressure-induced injury. This review presents a hypothesis that microalbuminuria reflects the early stage of vascular injury, especially strain vessels' injury, and that strain vessels' injury connects chronic kidney disease with the risk of cardiovascular disease.