Comparative effects of olmesartan and azelnidipine on atrial structural remodeling in spontaneously hypertensive rats.
The differential effects between olmesartan (OM), an angiotensin 2 type 1 receptor blocker (ARB), and azelnidipine (AZ), a calcium channel blocker (CCB), on atrial structural remodeling were studied in spontaneously hypertensive rats (SHR). Eight weeks after treatment, both OM and AZ decreased systolic blood pressure to similar levels. Histological analysis revealed that both OM and AZ had decreased the size of the atrial myocytes and interstitial fibrosis in the atrium, and that the effects of OM were greater than those of AZ. These beneficial effects of OM were associated with less atrial oxidative stress, as assessed by 3-nitrotyrosine staining, and less activation of Rac1, a regulatory component in NADPH oxidase. These results suggest that the ARB was more effective than the CCB in ameliorating atrial structural remodeling due to the suppression of oxidative stress.
Division of Cardiology, Niigata University Graduate School of Medicine and Dental Sciences, Niigata, Japan.
Kazuki
K
Okamura
Masahiro
M
Ito
Komei
K
Tanaka
Masaomi
M
Chinushi
Takeshi
T
Adachi
Wataru
W
Mitsuma
Satoru
S
Hirono
Mikio
M
Nakazawa
Makoto
M
Kodama
Yoshifusa
Y
Aizawa
D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology*; D000818:Animals; D001383:Azetidinecarboxylic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004095:Dihydropyridines / Q000494:pharmacology*; D006321:Heart / Q000033:anatomy & histology / Q000187:drug effects; D006325:Heart Atria / Q000033:anatomy & histology* / Q000187:drug effects* / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology*; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D011918:Rats, Inbred SHR; D013777:Tetrazoles / Q000494:pharmacology*; D020830:rac1 GTP-Binding Protein / Q000378:metabolism
D047228:Angiotensin II Type 1 Receptor Blockers; D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D007093:Imidazoles; D013777:Tetrazoles; D001383:Azetidinecarboxylic Acid; C437965:olmesartan; D020830:rac1 GTP-Binding Protein; C061679:azelnidipine