The aim of this study was to investigate whether the antihypertensive and renal effects of Ca2+ antagonists are related to the sodium state of the patients. For this purpose, in a group of 11 patients with essential hypertension we have compared the blood pressure lowering effects of a single oral dose of nifedipine before (100 mmol Na+/day and 40 mmol K+/day) and after sodium depletion (20 mmol Na+/day and 40 mmol K+/day: each period was of 6-8 day duration). During the normal sodium diet nifedipine significantly lowered supine blood pressure (from 185 +/- 13/107 +/- 7 to 161 +/- 13/100 +/- 7 mm Hg, p less than 0.001) and induced a significant rise in Na+ excretion (from 52 +/- 10 to 94 +/- 13 mmol/6 h) and in urine volume (from 520 +/- 80 to 947 +/- 120 ml/6 h; p less than 0.01). Sodium depletion significantly lowered supine blood pressure (152 +/- 12/95 +/- 9 mm Hg, p less than 0.001); nifedipine caused a further and significant blood pressure reduction (142 +/- 11/90 +/- 8 mm Hg, p less than 0.01), but only a minor and not significant increase in sodium excretion (from 10 +/- 2 to 22 +/- 5 mmol/6 h) and urine volume (from 338 +/- 76 to 463 +/- 94 ml/6 h). Our data suggest that the natriuretic action of calcium antagonists is not relevant to their antihypertensive effect.
|Titolo:||Effects of different sodium intakes on the antihypertensive and renal effects of single oral doses of nifedipine in hypertensive patients|
BOLLA, GIOVANNI BATTISTA (Penultimo)
|Parole Chiave:||Antihypertensive efficacy; Natriuretic and diuretic effect; Nifedipine; Sodium replete and deplete states|
|Settore Scientifico Disciplinare:||Settore MED/09 - Medicina Interna|
|Data di pubblicazione:||1987|
|Appare nelle tipologie:||01 - Articolo su periodico|