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Plasma Aldosterone Response to Angiotensin II in Sodium‐Restricted Elderly Subjects with Essential Hypertension
Author(s) -
MORIMOTO SHINPEI,
UCHIDA KENZO,
MIYAMOTO MASAJI,
KIGOSHI TOSHIKAZU,
MORISE TOSHIO,
TAKIMOTO HIROAKI,
TAKEDA RYOYU
Publication year - 1981
Publication title -
journal of the american geriatrics society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.992
H-Index - 232
eISSN - 1532-5415
pISSN - 0002-8614
DOI - 10.1111/j.1532-5415.1981.tb01269.x
Subject(s) - medicine , aldosterone , essential hypertension , sodium , endocrinology , angiotensin ii , renin–angiotensin system , cardiology , blood pressure , chemistry , organic chemistry
ABSTRACT The plasma aldosterone (PA) response to sodium restriction (25 mEq daily for 4 days) and to graded infusions of angiotensin II (AH, 2, 4 and 8 ng/kg/min each for 30 min) during a low‐sodium intake were studied in 15 elderly subjects with mild essential hypertension versus 10 elderly normotensive subjects. The PA reponse to sodium restriction relative to changes in plasma renin activity (PRA) was estimated by the ratio of PA increment to PRA increment after sodium restriction (ΔPA/ΔPRA). The PA response to graded AII infusions was determined by the increment of PA above the basal level after each dose of AII. In 10 of the 15 elderly hypertensive subjects whose PRAs responded normally to sodium restriction, the ΔPA/ΔPRA ratios and PA increments during the graded AII infusions were similar to those in the elderly normotensive subjects. However, in the remaining 5 elderly hypertensive subjects whose PRAs responded subnormally to sodium restriction, the ΔPA/ΔPRA ratios were high and the PA increments greater during the graded AII infusions. The increments of mean blood pressure during the graded AII infusions were similar in the foregoing 10 of 15 hypertensive subjects, and significantly greater during the AH infusion rates of 4 and 8 ng/kg/min in the remaining 5 hypertensive subjects when compared with those in the normotensive subjects. Apparently some elderly subjects with essential hypertension, whose PRAs respond subnormally to sodium restriction, have an abnormally enhanced adrenal responsiveness to AII under the condition of low‐sodium intake.