The mechanical properties of the arterial wall in hypertension.

In hypertensive patients, the buffering function of large arteries is constantly altered, due to modifications in the viscoelastic properties of the arterial wall. Several in vivo models of the arterial circulation have been described to determine arterial compliance in animals and humans. The pressure dependency of arterial compliance is the main difficulty in evaluating the mechanical properties of large arteries in hypertension and establishing whether reduced arterial compliance is the simple mechanical consequence of the blood pressure elevation or reflects intrinsic alterations of the arterial wall. In comparison with the normotensive population, the carotid arterial wall is stiffer in hypertensive rats and humans, due to abnormalities in both the structural and the functional components. Interestingly, the presence of an intact and normal endothelium greatly influence vasomotor tone. The pathways by which the intrinsic modifications of the arterial wall may be reversed following drug treatment remain difficult to delineate. However, such considerations are clearly of importance for antihypertensive therapy, the goal of which may be not only the reduction of blood pressure but also improvement of the status of the hypertensive abnormalities of the arterial system.