The Development and Regression of Vascular Hypertrophy

Abstract

Summary: 

Genetic hypertension [essential hypertension (EH) in humans and spontaneous hypertension in rats (SHRs)] is associated with an altered vascular structure, expressed in resistance vessels (small arteries) as an increased media:lumen ratio. The vascular smooth muscle cells appear normal and there is no cellular hypertrophy. The amount of smooth muscle may be increased in SHR resistance vessels (i.e., there is evidence for hyperplasia). Present evidence in EH indicates that there is no increase in vascular smooth muscle mass, suggesting that the altered structure is due to “remodeling,” a rearrangement of a normal amount of normal material. With antihypertensive therapy, reduction in mean blood pressure does not necessarily normalize vascular structure, and there are few grounds for supposing that one drug is better than another in this respect. Preliminary evidence suggests that normalization of the pulse pressure may be more important than normalizing mean blood pressure, if vascular structure is to be corrected. Although vascular structure may not per se be an important determinant of blood pressure, reduction in blood pressure without correcting vascular structure is undesirable. Thus, improvement of the means for correcting vascular structure may be an important way of improving prognosis with antihypertensive treatment.