Resistance Vessel Structure in Essential Hypertension

Abstract

As Folkow first proposed on the basis of experimental evidence (7), essential hypertension could be the consequence of a vicious circle between the structure of resistance vessels responding to, and then maintaining, increased blood pressure. Thus, the structural changes in the resistance vessels were seen as being both consequence and cause of hypertension. Furthermore, Folkow proposed that in the resistance arteries of patients with essential hypertension there is “a generalized wall thickening that partly takes place at the expense of the lumen”. These concepts, were based on the observation that the minimum vascular resistance of the forearm was increased in patients with essential hypertension and the histological evidence (9) that hypertension was associated with an increased wall:lumen ratio (8). Although this was probably not Folkow’s intention, these vascular changes in hypertension have been taken as indicating that vascular growth is an integral part of the pathogenesis of the disease. Interest in this possibility has greatly increased over the past decade, largely from the ability of molecular biologists to identify and characterize growth factors, thus opening the way to understand the apparent growth mechanisms involved (5). Here I will review briefly the evidence that essential hypertension is associated with growth in the resistance vasculature. The review is based on a review previously published in ref. 13.