Effects of the administration of beta-blockers on ventricular remodeling induced by cigarette smoking in rats.
BACKGROUND
The role of the adrenergic system on ventricular remodeling induced by cigarette smoking is unknown.


OBJECTIVE
To investigate the influence of propranolol on ventricular remodeling induced by exposure to tobacco smoke.


METHODS
Rats were divided into three groups: 1) C, n=10--control group; 2) F, n=10--animals exposed to tobacco smoke; 3) BB, n=10--animals receiving propranolol and exposed to tobacco smoke (40 mg/kg/day). After 2 months, the animals underwent echocardiographic and morphometric analyses. One-way ANOVA (mean +/- standard deviation) or the Kruskal-Wallis test (median and interquartile interval) was used.


RESULTS
Group BB showed a lower heart rate than group F (C = 358 +/- 74 bpm, F = 374 +/- 53 bpm, BB = 297 +/- 30; P = 0.02). Group F showed greater end-diastolic diameters (C = 18.6 +/- 3.4 mm/kg, F = 22.8 +/- 1.8 mm/kg, BB = 21.7 +/- 1.8 mm/kg; P = 0.003) and left ventricular (LV) end-systolic diameters (C = 8.6 +/- 2.1 mm/kg, F = 11.3 +/- 1.3 mm/kg, BB = 9.9 +/- 1.2 mm/kg; P = 0.004), adjusted for body weight (BW) and a tendency towards a lower ejection fraction (C = 0.90 +/- 0.03, F = 0.87 +/- 0.03, BB =0.90 +/- 0.02; P = 0.07) than group C. Group BB showed a tendency towards a lower LV/BW ratio than group F (C = 1.94 (1.87 - 1.97), F = 2.03 (1.9-2.1) mg/g, BB = 1.89 (1.86-1.94); P = 0.09).


CONCLUSIONS
Administration of propranolol attenuated some of the variables of ventricular remodeling induced by the exposure to tobacco smoke in rats.
Duarte
Daniella R
DR
Faculdade de Medicina de Botucatu, Botucatu, SP, Brasil.
Oliveira
Lucienne C
LC
Minicucci
Marcos F
MF
Azevedo
Paula S
PS
Matsubara
Beatriz B
BB
Matsubara
Luiz S
LS
Campana
Alvaro O
AO
Paiva
Sergio A R
SA
Zornoff
Leonardo A M
LA
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D019570:Inhalation Exposure / Q000009:adverse effects*; D008297:Male; D023421:Models, Animal; D011433:Propranolol / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D018487:Ventricular Dysfunction, Left / Q000188:drug therapy / Q000209:etiology* / Q000473:pathology; D020257:Ventricular Remodeling / Q000187:drug effects*
D000319:Adrenergic beta-Antagonists; D014028:Tobacco Smoke Pollution; D011433:Propranolol