Effect of spironolactone on cytosolic free sodium concentration in platelets from hypertensive patients with primary aldosteronism.
Cytosolic free sodium concentration ([Na+]i) was investigated in intact platelets from 5 hypertensive patients with primary aldosteronism (unilateral adenoma in 3 patients, and adrenal hyperplasia in 2 patients) and 21 normotensive control subjects. [Na+]i was measured using a novel sodium-sensitive fluorescent dye technique. [Na+]i was significantly decreased in platelets from patients with primary aldosteronism compared to control subjects (21.9 +/- 4.1 mM vs 35.8 +/- 2.2 mM, mean +/- SEM, P < 0.05). After administration of the mineralocorticoid antagonist spironolactone in 4 patients [Na+]i tended to be higher in platelets although the differences did not reach statistical significance (26.3 +/- 7.2 mM vs 18.2 +/- 2.4 mM, P = 0.125). From the present results it may be concluded that intracellular sodium is decreased by aldosterone-induced activation of Na-K-ATPase. That activation may be partly blocked by spironolactone.
Medizinische Universitätspoliklinik, University of Münster, Germany.
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M
Tepel
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Husseini
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W
Zidek
D000368:Aged; D000369:Aged, 80 and over; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D001794:Blood Pressure / Q000187:drug effects; D003404:Creatinine / Q000097:blood; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D005260:Female; D006801:Humans; D006929:Hyperaldosteronism / Q000097:blood*; D006973:Hypertension / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010783:Photometry; D011188:Potassium / Q000097:blood; D012964:Sodium / Q000097:blood*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors; D013148:Spironolactone / Q000494:pharmacology*
D013148:Spironolactone; D012964:Sodium; D003404:Creatinine; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium