Antihypertensive treatment normalizes decreased endothelium-dependent relaxations in rats with salt-induced hypertension.
Endothelium-dependent responses are impaired in various models of hypertension. The effects of antihypertensive treatment on endothelium-dependent relaxations were studied in Dahl salt-sensitive (DS) and Dahl salt-resistant rats (DR) on a high or low sodium diet. The rats were given either a diet containing 8% NaCl or 0.1% NaCl for 8 weeks or a diet containing 8% NaCl and a combination of reserpine, hydrochlorothiazide, and hydralazine for 8 or 2 weeks. DS on the 8% NaCl diet developed hypertension, while the other rats did not. Antihypertensive therapy for 8 or 2 weeks prevented or reversed hypertension in DS and lowered blood pressure in DR on the 8% NaCl diet. Aortic rings with and without endothelium were suspended in organ chambers for isometric tension recording. In all groups, acetylcholine, adenosine 5'-diphosphate, and thrombin caused endothelium-dependent relaxations. The relaxations in response to all agonists were significantly decreased in DS on 8% NaCl compared to relaxations in the other rats. Antihypertensive treatment for 8 or 2 weeks prevented or reversed the decreased endothelium-dependent relaxations in response to all agonists tested, but not those to the endothelium-independent agonist, sodium nitroprusside. These results suggest that antihypertensive treatment normalizes endothelium-dependent relaxations. This effect of antihypertensive treatment might be important for the prevention of cardiovascular complications in patients with hypertension.
D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001011:Aorta / Q000503:physiopathology; D001794:Blood Pressure / Q000187:drug effects; D004039:Diet, Sodium-Restricted; D004351:Drug Resistance; D004727:Endothelium / Q000503:physiopathology*; D006973:Hypertension / Q000139:chemically induced / Q000503:physiopathology*; D008297:Male; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats; D012965:Sodium Chloride; D014661:Vasoconstriction; D014664:Vasodilation / Q000187:drug effects*
D000959:Antihypertensive Agents; D009599:Nitroprusside; D012965:Sodium Chloride