Influência da restrição dietética de vitamina A na redemodelação cardíaca pós-infarto

Abstract

o objetivo de nosso estud a a Isa _ alimentar de vitamina A sobre a remodelação cardíaca a miocárdio em ratos. Métodos: Foram utilizadas ratas previamente hígidas, submetidas durante a gestação e lactação a duas dieta AIN-93 isenta de vitamina A + 4 REfg de dieta (dose fisiológica); 2) dieta AIN-93 isenta de vitamina A. Após o nascimento dos filhotes, os machos foram separados em gaiolas individuais. Os filhotes das ratas tratadas com dieta com dose fisiológica de vitamina A continuaram recebendo 4REfg de dieta e os filhotes das ratas tratadas com dieta isenta de vitamina A receberam 0.18 RE{g de dieta. Quando atingiram, aproximadamente 220 g, os ratos foram submetidos ao infarto experimental. Após 24 horas do procedimento os ratos foram divididos em grupo controle (Grupo C, n

The aim of this study was to ana vitamin A ingestion on cardiac remodeling after myocardial infarction in rats. Methods: wistar female rats during pregnancy and lactation were fed with two diets: 1) AIN-93 vitamin A sufficient diet (4 RE/g af diet) and 2) AIN-93 vitamin A free diet. After born, male rats were studied. Newborns from dams fed with AIN93 vitamin A ft-ee diet, aftet- weaning received AIN-93 with 0,18 RE(g of diet. Newborns from dams fed with AIN-93 vitamin A sufficient diet, after weaning, received the same diet until they were around 220 g~With 220 g the animaIs were submitted to myocardial infarction. After 24 hours from the procedure, the surviving rats were divided into two groups: contrai group (C group, n=25) that remain receiving AIN-93 vitamin A sufficient diet; and reduced vitamin A group (RVA group, n=26) that remain receiving AIN-93 with O,lB REfg of diet. The groups were observed during 3 months. After this period, they were submitted to morphometric, functional and biochemical analysis. Statistical analysis was performed with Student t-test and Mann-Whitney for comparisons between two groups when variables were continuous, and x2 when variables were categorical. The significant leveI was 5%. Results: There was no difference in weight at infarction moment and infarct size between the two groups (C=36,9 ± 9,6 %; RVA=36,3 ± B,9 %; p=O,BB). The mortality during the 3 months period after infarction was not different between the groups (C=4B%; RVA=50%, p=0,B91). RVA group showed higher aorta diameter [C=3,4 (3,1-3,6) mm; RVA=3,5 (3,43,9) mm, p=0,04], left ventricle diastolic diameter (C=9,4 ± 1,4 mm; RVA=10,5 ± 1,2 mm, p=0,04) and diastolic area in short axes(body weight(C=l,B ± 0,4 cm2fkg; RVA=2,1 ± 0,3 cm2fkg, p=0,03) than C group. Cansidering the variables that represent diastolic function, RVA group showed lower TRIV(RRO,5than C group... (Complete abstract click electronic access below)