Arquivos Brasileiros de Cardiologia (Jul 2009)
Papel da lipoperoxidação na intensificação da remodelação causada pelo betacaroteno após o infarto Rol de la lipoperoxidación en la intensificación de la remodelación ocasionada por el betacaroteno tras infarto Role of lipoperoxidation in the remodeling intensification induced by beta-carotene after infarction
Abstract
FUNDAMENTO: Os mecanismos envolvidos na maior remodelação causada pelo betacaroteno após o infarto são desconhecidos. OBJETIVO: Analisar o papel da lipoperoxidação na remodelação ventricular após o infarto do miocárdio, em ratos suplementados com betacaroteno. MÉTODOS: Ratos foram infartados e distribuídos em dois grupos: C (controle) e BC (500mg/kg/dieta). Após seis meses, foram realizados ecocardiograma e avaliação bioquímica. Utilizamos o teste t, com significância de 5%. RESULTADOS: Os animais do grupo BC apresentaram maiores médias das áreas diastólicas (C = 1,57 ± 0,4 mm²/g, BC = 2,09 ± 0,3 mm²/g; p FUNDAMENTO: Los mecanismos implicados en la mayor remodelación ocasionada por betacaroteno tras el infarto son desconocidos. OBJETIVO: Analizar el rol que juega la lipoperoxidación en la remodelación ventricular tras el infarto de miocardio, en ratas suplementadas con betacaroteno. MÉTODOS: Se había inducido a un infarto a las ratas y se las distribuyó en grupos: C (control) y BC (500mg/kg/dieta). Tras seis meses, se realizaron ecocardiograma y evaluación bioquímica. Utilizamos la prueba t, con significancia del 5%. RESULTADOS: Los animales del grupo BC presentaron mayores promedios de las áreas diastólicas (C = 1,57 ± 0,4 mm²/g, BC = 2,09 ± 0,3 mm²/g; p BACKGROUND: The mechanisms involved in the biggest remodeling caused by the post-infarct beta-carotene are unknown. OBJECTIVE: To analyze the role of lipoperoxidation in the ventricular remodeling after infarct of the myocardium in rats supplemented with beta-carotene. METHODS: Rats were infarcted and divided into two groups: C (control) and BC (500mg/kg/regimen). After six months, echocardiogram and biochemical evaluation were performed. The t test was used, with 5% significance. RESULTS: The animals from BC group presented highest means of the diastolic (C = 1.57 ± 0.4 mm²/g, BC = 2.09 ± 0.3 mm²/g; p < 0.001) and systolic (C = 1.05 ± 0.3 mm²/g, BC = 1.61 ± 0.3 mm²/g; p < 0.001) areas of LV, which were adapted according to the rat's body weight. The systolic function of LV, evaluated by the area variation fraction, was lower in the animals supplemented with beta-carotene (C = 31.9 ± 9.3%, BC = 23.6 ± 5.1%; p = 0.006). The animals supplemented with beta-carotene presented higher values of the E/A relation (C = 2.7 ± 2.5, BC = 5.1 ± 2.8; p = 0.036). No differences were found between the groups concerning the cardiac levels of the GSH (C = 21 ± 8 nmol/mg of protein, BC = 37 ± 15 nmol/mg of protein; p = 0.086), GSSG (C = 0.4 (0.3-0.5) nmol/g of protein, BC = 0.8 (0.4-1.0; p = 0.19) of protein; p = 0.246) and lipoperoxides (C = 0.4 ± 0.2 nmol/mg of tissue, BC = 0.2 ± 0.1 nmol/mg of tissue; p = 0.086). CONCLUSION: The highest remodeling in infarcted rats supplemented with beta-carotene does not depend on the lipoperoxidation.
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