title: Intracellular electrolytes during antihypertensive treatment with a loop diuretic.
abstract: The effect of the loop diuretic, piretanide (12 mg/day on blood pressure and intracellular electrolyte composition in red blood cells during a six-week treatment period was studied in 14 previously untreated essential hypertensive patients. Blood pressure fell continuously during the six weeks, intracellular Na+ activity in red blood cells increased slightly (P less than 0.05), and there was a marked decrease in intracellular Ca2+ activity (P less than 0.01). Intracellular K+ concentration was not altered. It is concluded therefore, that intracellular free Na+ does not correlate with the actual blood pressure, whereas the fall in blood pressure is associated with a decrease in intracellular free Ca2+, suggesting that intracellular free Ca2+ is involved in the regulation of vascular tone.
mesh_terms: D000328:Adult; D000368:Aged; D004232:Diuretics / Q000627:therapeutic use*; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D012964:Sodium / Q000097:blood; D013449:Sulfonamides / Q000627:therapeutic use*
chemical_list: D004232:Diuretics; D013449:Sulfonamides; D012964:Sodium; C015451:piretanide; D011188:Potassium