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Exposure time and ventricular remodeling induced by tobacco smoke exposure in rats

Edson Castardeli, Daniella R. Duarte, Marcos F. Minicucci, Paula S. Azevedo, Beatriz B. Matsubara, Luiz S. Matsubara, Alvaro O. Campana, Sergio A.R. Paiva, Leonardo A.M. Zornoff

Med Sci Monit 2008; 14(3): BR62-66

ID: 836573

Published: 2008-02-27


Background: We investigated the effects of length of exposure to tobacco smoke on the cardiac remodeling process induced by exposure to cigarette smoke in rats.
Material and Method: Rats were separated into 4 groups: nonsmoking (NS)2 (n=25; control animals not exposed to tobacco smoke for 2 months), smoking (S)2 (n=22; rats exposed to smoke from 40 cigarettes/d for 2 months), NS6 (n=18; control animals not exposed to tobacco smoke for 6 months), and S6 (n=25; rats exposed to smoke from 40 cigarettes/d for 6 months). All animals underwent echocardiographic, isolated heart, and morphometric studies. Data were analyzed with a 2-way analysis of variance.
Results: No interaction among the variables was found; this suggests that length of exposure to tobacco smoke did not influence the effects of exposure to smoke. Values for left ventricular diastolic diameter/body weight and left atrium/body weight were higher (p=0.023 and p=0.001, respectively) in smoking (S2 and S6) than in nonsmoking animals (NS2 and NS6). Left ventricular mass index was higher (p=0.048) in smoking than in nonsmoking animals. In the isovolumetrically beating ventricle, peak systolic pressure was higher (p=0.034) in smoking than in nonsmoking animals. Significantly higher values were found for left ventricular weight (p=0.017) and right ventricular weight (p=0.001) adjusted for body weight in smoking as opposed to nonsmoking animals. Systolic pressure was higher (p=0.001) in smoking (128+/-14 mm Hg) than in nonsmoking animals (112+/-11 mm Hg).
Conclusions: Length of exposure to cigarette smoke did not influence cardiac remodeling caused by exposure to smoke in rats.

Keywords: Ventricular Function, Right, Ventricular Function, Left, Smoking - adverse effects, Rats, Wistar, Rats, Ventricular Remodeling, Male, Animals



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