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Updated: Jun 23, 2026

A Model of Cardiac Remodeling Through Constriction of the Abdominal Aorta in Rats
Published on: December 2, 2016
Comparative effects of olmesartan and azelnidipine on atrial structural remodeling in spontaneously hypertensive rats
Kazuki Okamura1, Masahiro Ito, Komei Tanaka
1Division of Cardiology, Niigata University Graduate School of Medicine and Dental Sciences, Niigata, Japan.
Abstract:
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.
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