Mobilization of antioxidant vitamin pools and hemodynamic function after myocardial infarction

Background-Although most previous studies have attempted to correlate plasm a concentrations of vitamins with specific cardiovascular end points, metab olic considerations suggest that changes in myocardial tissue and storage o rgans may be better indicators of myocardial oxidative stress. Methods and Results-Rats fed commercial chow or a diet enriched with vitami n E for 2 weeks were subjected to either a surgical myocardial infarction ( MI) or a sham procedure. Rats were hemodynamically assessed 16 weeks after surgery, and their heart, liver, kidney, and plasma were analyzed for antio xidant vitamins E (tocopherol) and A (retinol and total retinyl esters). At 16 weeks, MI rats on a control diet showed depressed peak systolic and ele vated diastolic pressures in both right and left ventricles compared with t heir sham controls. Plasma concentrations of vitamins E and A in MI fats we re not different from sham controls fed the same diet. However, concentrati ons of vitamin E in left ventricle and liver and of vitamin A in liver (ret inol) and kidney (retinyl esters) were decreased in rats with MI compared w ith the sham controls. Vitamin E supplementation improved hemodynamic funct ion in rats with MI and increased plasma, myocardial, liver, and kidney con centrations of vitamin E. The vitamin E diet also prevented the loss of tot al retinyl esters from the kidney but not of retinol from the liver in MI r ats. Conclusions-Dietary supplements of vitamin E can sustain better cardiac fun ction subsequent to MI. Antioxidant vitamin levels in the myocardium or in storage organs and not in plasma may be better indicators of myocardial oxi dative stress.