Effects of calcium antagonists on deranged modulation of the renal function curve in salt-sensitive patients with essential hypertension.

Two subsets of patients with essential hypertension have been identified based on their sensitivity to dietary sodium intake: the salt-sensitive and the salt-resistant patients. The renal function curve in salt-resistant patients is shifted to higher blood pressure levels but it remains parallel to that of normal subjects. On the contrary, the slope of the renal function curve in salt-sensitive patients is considerably depressed. It is postulated that this derangement may be related to an abnormal relation between sodium intake and sympathetic nervous system activity. It is also postulated that a link exists between abnormalities of sodium and calcium metabolism in hypertension and that reduced renin release, increased sympathetic activity and reduced renal sodium excretion in salt-sensitive patients may be related to a defect in sodium-linked cellular calcium transport. Calcium antagonists revert the derangements in the renal function curve and in renin release in salt-sensitive patients.