Vitamin E deficiency fails to affect myocardial performance during in vivoischemia-reperfusion

Vitamin E content of cardiac tissue has been proposed to play a major role in the damage caused by myocardial ischemia-reperfusion (I-R). Previous stu dies using in vitro models have examined vitamin E deficiency and I-R-induc ed myocardial damage with equivocal results. The purpose of this study was to use an in vivo model of myocardial T-R to determine the effects of vitam in E deficiency on myocardial I-R-induced damage. Female Sprague-Dawley rat s (4-mo old) were assigned to either: 1) control diet (CON), or 2) vitamin E deficient diet (VE-DEF). The CON diet was prepared to meet AIN-93M standa rds, which contains 75 IU vitamin E/kg diet. The VE-DEF diet was the AIN-93 M diet prepared with tocopherol stripped corn oil and no vitamin E, Followi ng a 14-week feeding period, significant differences (p < 0.05) existed in mean myocardial VE levels between groups (mean values +/- SEM: CON = 48.2 /- 3.5; VE-DEF = 12.4 +/- 1.4 mug VE/g wet weight). Animals from both exper imental groups were subjected to an in vivo I-R protocol consisting of 25 m inutes of left coronary artery occlusion followed by 10 minutes of reperfus ion. No group differences (p > 0.05) existed in cardiac performance (peak a rterial pressure or ventricular work) or the incidence of ventricular arrhy thmias during the I-R protocol. VE-DEF animals had significantly higher (p < 0.05) levels of myocardial lipid peroxidation and lower (p < 0.05) protei n thiols following I-R compared to the CON animals. These data suggest that although vitamin E deficiency increases oxidative damage resulting from my ocardial I-R, it does not affect cardiac performance during the insult.