Mechanical and other factors involved in vascular injury related to hypertension.

In essential hypertension, the structure of the resistance vessels is altered such that the internal diameter (lumen) is reduced and the ratio of the tunica media thickness to the lumen is increased. This abnormality appears to be associated more with remodelling than with growth. Thus, normalization of resistance vessel structure must be aimed both at reversing the remodelling as well as inhibiting growth. Present evidence concerning the effect of antihypertensive therapy on vascular structure suggests that the effect of such therapy on vascular structure is due more to remodelling than to growth inhibition. However, the effect on vascular structure appears to be insufficient as antihypertensive therapy is better able to reduce blood pressure than to normalize vascular structure. It is suggested that the possible role of vascular remodelling in essential hypertension requires further work, and that this may have consequences for future strategies in the development of antihypertensive drugs.