CE inhibition and natriuresis with ramipril in conscious SHR: different modes of action of loop and thiazide diuretics.
Acute effects of piretanide, a loop diuretic, on blood pressure (BP) and urinary output as well as long-term effects on serum electrolytes were compared in conscious spontaneously hypertensive rats (SHR) to that of hydrochlorothiazide (HCT) both given alone and in combination with the converting enzyme (CE) inhibitor ramipril. There were no acute or chronic falls in BP with low doses of either diuretic. Ramipril at a dose of 10 mg/kg normalized BP, which was accompanied by initial natriuresis and, over the long term, K+ preservation. Minimally effective doses of piretanide but not HCT given in combination with 1 mg/kg ramipril produced a greater fall in BP both acutely and chronically than ramipril alone at unaltered K+ preservation. To match this fall in BP with HCT, large doses were required, which caused hemoconcentration and impaired K+ preservation.
Becker
R H
RH
Hoechst AG, Frankfurt, F.R.G.
Baldes
L
L
Treudler
M
M
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D001643:Bridged Bicyclo Compounds / Q000494:pharmacology*; D004232:Diuretics; D006852:Hydrochlorothiazide / Q000494:pharmacology; D008138:Loop of Henle / Q000187:drug effects*; D008297:Male; D009318:Natriuresis / Q000187:drug effects*; D017257:Ramipril; D051381:Rats; D011918:Rats, Inbred SHR; D049993:Sodium Chloride Symporter Inhibitors / Q000494:pharmacology*; D013449:Sulfonamides / Q000494:pharmacology
D000806:Angiotensin-Converting Enzyme Inhibitors; D001643:Bridged Bicyclo Compounds; D004232:Diuretics; D049993:Sodium Chloride Symporter Inhibitors; D013449:Sulfonamides; D006852:Hydrochlorothiazide; C015451:piretanide; D017257:Ramipril