An Angiotensin Receptor Blocker Prevents Arrhythmogenic Left Atrial Remodeling in a Rat Post Myocardial Infarction Induced Heart Failure Model
Journal of Korean Medical Science
;
: 700-708, 2013.
Article
in English
| WPRIM
| ID: wpr-80579
ABSTRACT
This study investigated the role of angiotensin II receptor blocker in atrial remodeling in rats with atrial fibrillation (AF) induced by a myocardial infarction (MI). MIs were induced by a ligation of the left anterior descending coronary artery. Two days after, the rats in the losartan group were given losartan (10 mg/kg/day for 10 weeks). Ten weeks later, echocardiography and AF induction studies were conducted. Ejection fraction was significantly lower in the MI rats. Fibrosis analysis revealed much increased left atrial fibrosis in the MI group than sham (2.22 +/- 0.66% vs 0.25 +/- 0.08%, P = 0.001) and suppression in the losartan group (0.90 +/- 0.27%, P 0.001) compared with the MI group. AF inducibility was higher in the MI group than sham (39.4 +/- 43.0% vs 2.0 +/- 6.3%, P = 0.005) and significantly lower in losartan group (12.0 +/- 31.6%, P = 0.029) compared with the MI. The left atrial endothelial nitric oxide synthase (NOS) and sarco/endoplasmic reticulum Ca(2+)-ATPase levels were lower in the MI group and higher in the losartan group significantly. The atrial inducible NOS and sodium-calcium exchanger levels were higher in the MI and lower in the losartan group significantly. Losartan disrupts collagen fiber formation and prevents the alteration of the tissue eNOS and iNOS levels, which prevent subsequent AF induction.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Atrial Fibrillation
/
Fibrosis
/
Receptors, Angiotensin
/
Immunohistochemistry
/
Rats, Sprague-Dawley
/
Losartan
/
Sodium-Calcium Exchanger
/
Disease Models, Animal
/
Nitric Oxide Synthase Type II
/
Nitric Oxide Synthase Type III
Limits:
Animals
Language:
English
Journal:
Journal of Korean Medical Science
Year:
2013
Type:
Article
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