Ion transport defects and hypertension. Where is the link?

large body of literature on the cellular pathophysiology of essential hypertension is focused on a variety of membrane transport systems that control the intracellular ionic milieu and thus have the potential to regulate vascular smooth muscle contractile activity. Defects in one or more of these transport systems have been proposed to play an important role in the pathogenesis of hypertension. Aviv and Gardner, 1 in this issue of Hypertension, attempt to explain the marked differences in the disease among blacks and whites in terms of the cellular handling of Na + and Ca 2+ ions in vascular smooth muscle cells and in renal epithelial cells. These are provocative ideas that require further examination. However, it is important to balance them with a critical examination of the relations that are currently believed to exist between cellular Na + , Ca 2+ , vascular smooth muscle contractile force, and hypertension.