ABSTRACT
Hypertension is the clinical manifestation of an increased total peripheral resistance, resulting from intensified contractions of the peripheral resistance vessels. In the light of the epidemiological evidence supporting links between Sodium (Na)-metabolism dysfunction and hypertension, it would seem that studies using human resistance vessels are required. The predominance of the Na ion in the extracellular fluid and the often stated universal role of calcium (Ca) ions in controlling physiological processes, make it highly probable that interactions between these two ions should have important physiological consequences. The quest for specific inhibitors of Na:Ca exchange has focused on using di- and trivalent cations to displace bound Ca and/or Na from their respective binding sites. The theory of Na:Ca exchange has evolved from being no more than mutual antagonism of the principle cations, into a mechanism believed to be intimately involved in stimulus-response coupling in cardiac and neural tissue, under both physiological and pathophysiological conditions.
