R. Maeso et al., Differential effects of losartan and doxazosin on vascular function in senescent spontaneously hypertensive rats, AM J HYPERT, 12(11), 1999, pp. 1105-1108
We evaluated the effects of treatment for 12 weeks with 10 mg/kg/day of eit
her losartan or doxazosin on vascular function in senescent spontaneous hyp
ertensive rats (SHR). Both doxazosin and losartan reduced blood pressure, a
lthough the former was more effective. In contrast, both drugs reduced rela
tive aortic weight and increased plasma nitrates to a similar extent. Losar
tan, but not doxazosin, increased the magnitude of the response to acetylch
oline (10(-9) to 10(-5) mol/L). Both treatments increased relaxations to so
dium nitroprusside (10(-10) to 10(-6) mol/L). These data show that losartan
may possess advantages over doxazosin in improving vascular function in se
nescent SHR. This report emphasizes the importance of angiotensin II in vas
cular function alterations induced by aging in SHR. (C) 1999 American Journ
al of Hypertension, Ltd.