Microcirculation in hypertension

Abstract

The microcirculation is a major site of control of vascular resistance. Direct measurement of pressure profiles within different segments of the microcirculation show that arterioles with an internal diameter of 150 μm or less contribute more than 70% to the total peripheral resistance. Apart from the diameters of individual arterioles, the numbers of microvessels and the way they are arranged determine resistance properties of microvascular beds. The importance of microvascular architecture in controlling resistance has led to a recent focus in research on the role of microvascular growth in cardiovascular pathophysiology. A decreased density of both arterioles and capillaries has been found in hypertension. In this article we discuss major mechanisms of microvascular density changes in hypertension. Furthermore, we indicate possibilities to design future therapies based on restoring normal microvascular densities.