Differential effects of losartan and doxazosin on vascular function in senescent spontaneously hypertensive rats.
We evaluated the effects of treatment for 12 weeks with 10 mg/kg/day of either losartan or doxazosin on vascular function in senescent spontaneous hypertensive rats (SHR). Both doxazosin and losartan reduced blood pressure, although the former was more effective. In contrast, both drugs reduced relative aortic weight and increased plasma nitrates to a similar extent. Losartan, but not doxazosin, increased the magnitude of the response to acetylcholine (10(-9) to 10(-5) mol/L). Both treatments increased relaxations to sodium nitroprusside (10(-10) to 10(-6) mol/L). These data show that losartan may possess advantages over doxazosin in improving vascular function in senescent SHR. This report emphasizes the importance of angiotensin II in vascular function alterations induced by aging in SHR.
Maeso
R
R
Department of Physiology, School of Medicine, Universidad Complutense, Madrid, Spain.
Navarro-Cid
J
J
Rodrigo
E
E
Ruilope
L M
LM
Lahera
V
V
Cachofeiro
V
V
D000109:Acetylcholine / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000375:Aging; D000804:Angiotensin II / Q000378:metabolism; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001011:Aorta / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology*; D001794:Blood Pressure / Q000187:drug effects; D017292:Doxazosin / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D006973:Hypertension / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology*; D019808:Losartan / Q000494:pharmacology*; D008297:Male; D009566:Nitrates / Q000097:blood; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D011945:Receptors, Angiotensin / Q000187:drug effects / Q000378:metabolism; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology
D000317:Adrenergic alpha-Antagonists; D000959:Antihypertensive Agents; D009566:Nitrates; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D011945:Receptors, Angiotensin; D014665:Vasodilator Agents; D000804:Angiotensin II; D009599:Nitroprusside; D019808:Losartan; D000109:Acetylcholine; D017292:Doxazosin