![]() |
|
|
Departamento de Clínica Médica, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista (UNESP), Botucatu, Brazil
3To whom correspondence should be addressed. E-mail: Paiva{at}fmb.unesp.br.
The objective of this study was to investigate the effects of exposure to tobacco smoke (ETS) in rats that were or were not supplemented with dietary ß-carotene (BC), on ventricular remodeling and survival after myocardial infarction (MI). Rats (n = 189) were allocated to 4 groups: the control group, n = 45; group BC administered 500 mg/kg diet, n = 49, BC supplemented rats; group ETS, n = 55, rats exposed to tobacco smoke; and group BC+ETS, n = 40. Wistar rats weighing 100 g were administered one of the treatments until they weighed 200 to 250 g (
5 wk). The ETS rats were exposed to cigarette smoke for 30 min 4 times/d, in a chamber connected to a smoking device. After reaching a weight of 200250 g, rats were subjected to experimental MI (coronary artery occlusion) and mortality rates were determined over the next 105 d. In addition, echocardiographic, isolated heart, morphometrical, and biochemical studies were performed. Mortality data were tested using Kaplan-Meyer curves and other data by 2-way ANOVA. Survival rates were greater in the ETS group (58.2%) than in the control (33.3%) (P = 0.001) and BC+ETS rats (30.0%) (P = 0.007). The groups did not differ in the other comparisons. Left ventricular end-diastolic diameter normalized to body weight was greater and maximal systolic pressures were lower in the ETS groups than in non-ETS groups. Previous exposure to tobacco smoke induced a process of cardiac remodeling after MI. There is a paradoxical protector effect with tobacco smoke exposure, characterized by lower mortality, which is offset by BC supplementation.
KEY WORDS: smoking ventricular remodeling ß-carotene paradoxical effect myocardial infarction
This article has been cited by other articles:
![]() |
A. Hozawa, D. R. Jacobs Jr., M. W. Steffes, M. D. Gross, L. M. Steffen, and D.-H. Lee Relationships of Circulating Carotenoid Concentrations with Several Markers of Inflammation, Oxidative Stress, and Endothelial Dysfunction: The Coronary Artery Risk Development in Young Adults (CARDIA)/Young Adult Longitudinal Trends in Antioxidants (YALTA) Study Clin. Chem., March 1, 2007; 53(3): 447 - 455. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. A. M. Zornoff, L. S. Matsubara, B. B. Matsubara, M. P. Okoshi, K. Okoshi, M. Dal Pai-Silva, R. F. Carvalho, A. C. Cicogna, C. R. Padovani, E. L. Novelli, et al. Beta-Carotene Supplementation Attenuates Cardiac Remodeling Induced by One-Month Tobacco-Smoke Exposure in Rats Toxicol. Sci., March 1, 2006; 90(1): 259 - 266. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. A. R. Paiva, L. S. Matsubara, B. B. Matsubara, M. F. Minicucci, P. S. Azevedo, A. O. Campana, and L. A. M. Zornoff Retinoic Acid Supplementation Attenuates Ventricular Remodeling after Myocardial Infarction in Rats J. Nutr., October 1, 2005; 135(10): 2326 - 2328. [Abstract] [Full Text] [PDF] |
||||