RECENT ADVANCES ON LARGE ARTERIES IN HYPERTENSION

The most classic hemodynamic concept explaining the increased mean art erial pressure in hypertension reflects an increased total peripheral resistance dynamically and an increased wall-to-lumen ratio to suppres s smaller arteries. However, a more current consideration takes into a ccount not only that steady component but also the pulsatile component of blood pressure, a point that importantly modifies the traditional hemodynamic definition. Whereas mean arterial pressure is almost const ant along the arterial tree, the pulse pressure increases markedly fro m the more central to the peripheral arteries, indicating that in vivo each artery should be characterized according to its own blood pressu re curve. This important concept implies major modifications in the me thods used to investigate the relationships between mechanical factors and large artery structure and function. It therefore seems reasonabl e that in hypertension the large arteries should no longer be consider ed as passive conduits but rather in terms of their active behavioral response to the mechanical forces to which they are subjected. New inv estigational aspects in hypertension therefore now involve not only ge neric, cellular, and molecular mechanisms but also transductional hemo dynamic mechanisms reflecting changing patterns in the extracellular m atrix that influence structural remodeling of the vessels.