J. Varagic et al., Coronary hemodynamic and ventricular responses to angiotensin type 1 receptor inhibition in SHR - Interaction with angiotensin type 2 receptors, HYPERTENSIO, 37(6), 2001, pp. 1399-1403
Citations number
50
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
This study was designed to determine the effects of angiotensin II type 1 (
AT(1)) receptor inhibition on coronary hemodynamics and ventricular mass an
d hydroxyproline content and the additive effects of angiotensin II type 2
(AT(2)) receptor inhibition in spontaneously hypertensive rats (SHR). The s
elective AT(1) receptor antagonist candesartan (10 mg/kg per day) was admin
istered alone or in combination with the AT(2) receptor antagonist PD 12331
9 (50 mg/kg per day) for 12 weeks. Control SHR received placebo for the sam
e period. Left and right ventricular coronary blood flow, blood flow reserv
e, and minimal coronary vascular resistance were determined by using radiom
icrospheres in male 35-week-old rats. Mean arterial pressure; total periphe
ral resistance; left and right ventricular, renal, and aortic weights; and
hydroxyproline concentration were also determined. Candesartan reduced mean
arterial pressure and left ventricular, renal, and aortic masses, as well
as hydroxyproline concentration and minimal coronary vascular resistance of
both ventricles. PD 123319 partially prevented the hypotensive effect of A
T(1) receptor inhibition and reversed the effect on myocardial hydroxyproli
ne concentration. These data suggest that AT(2) receptors contribute to the
hypotensive and antifibrotic effects but not the coronary hemodynamic impr
ovement or reduced left ventricular mass of AT(1) receptor inhibition in th
ese adult SHR.