ISSN:
1435-1803
Keywords:
Key words Nontransmural myocardial infarction – remodeling – transforming growth factor – captopril – losartan
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract With the application of early reperfusion therapy after acute MI, the incidence and importance of nontransmural infarction is increasing. In a rat model with nontransmural infarction, we evaluated 1) the changes of LV dimension, LV interstitial fibrosis and transforming growth factor-β1 (TGF-β1) mRNA expression and 2) the effects of angiotensin converting enzyme (ACE) inhibitor and angiotensin II type 1 (AT1) receptor antagonist treatment. Female Sprague-Dawley rats were subjected to 45 min of coronary occlusion followed by reperfusion, and five days after the operation the animals were randomized to untreated (n = 19), captopril-treated (n = 15) and losartan-treated (n = 14) groups. Twenty-six days after MI, echocardiographic examination revealed a remarkable dilatation of LV. Captopril or losartan treatment reduced the extent of LV cavity dilatation. Collagen volume fractions in noninfarcted septum as well as in peri-infarct area decreased with captopril or losartan treatment, compared to those of the untreated rats. In noninfarcted septum of untreated rats, TGF-β1 mRNA expression increased more than two fold (P 〈 0.05 vs. pre-MI) 5 and 10 days after MI. Captopril or losartan treatment suppressed the acute induction of TGF-β1 mRNA expressions. These results indicate that ACE inhibitor or AT1 receptor antagonist treatment after nontransmural infarction 1) attenuates LV remodeling as in transmural infarction and 2) decreases interstitial fibrosis at least partly by blocking the acute induction of TGF-β1 mRNA expression.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s003950050149
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