Effect of orally administered alpha-tocopheryl acetate on human myocardial alpha-tocopherol levels

Free radical injury may contribute to the delayed postoperative recovery of myocardial metabolism and ventricular function after elective coronary artery revascularization. This clinical study was designed to evaluate, in stable angina patients having aortocoronary bypass surgery [1], whether orally administered alpha-tocopheryl acetate was effective in increasing myocardial alpha-tocopherol levels and [2] the effect of cardioplegic arrest followed by reperfusion on the myocardial alpha-tocopherol levels. Twenty-four patients with stable angina pectoris for elective revascularization received preopertatively the natural stereoisomer of alpha-tocopheryl acetate labelled with deuterium (D3) and six patients were used as controls. Since four patients who received 300 mg of D3-alpha-tocopheryl acetate preoperatively for 1 and 2 days did not have significant increases in their myocardial total or D3-tocopherol levels, the remaining 20 patients received 100 mg (n=6), 300 mg (n=8), or 900 mg (n=6) of D3-alpha-tocopheryl acetate for 14 consecutive preoperative days. The left ventricular deuterated and non-deuterated alpha-tocopherol levels were measured by gas chromatography/mass spectrometry. Although there was a decrease (p < 0.05) in myocardial alpha-tocopherol levels with the onset of reperfusion (cross-clamp removal), the myocardial tocopherol levels were not statistically different from preoperative levels by 20 minutes of reperfusion. At least 300 mg of alpha-tocopherol must be taken orally for 14 consecutive days to double the myocardial alpha-tocopherol levels. \ua9 1991 Kluwer Academic Publishers.Peer reviewed: YesNRC publication: Ye

Myocardial salvage with trolox and ascorbic acid for an acute evolving infarction

Both Trolox (a water-soluble analogue of \u3b1-tocopherol) and ascorbic acid were more effective than superoxide dismutase or catalase in protecting myocyte cell cultures from free radical attack (induced by hypoxanthine and xanthine oxidase). In a canine model of two hours of left anterior descending coronary artery occlusion followed by four hours of reperfusion, Trolox and ascorbic acid reduced the area of infarction within the area at risk. The Trolox group received 500 mL of deoxygenated saline solution containing 2.0 g of Trolox, 3.0 g of ascorbic acid, and 18 mg of EDTA (ethylenediaminetetraacetic acid) infused into the ascending aorta 30 seconds before and four minutes after reperfusion. Saline controls received 500 mL of deoxygenated saline solution containing 18 mg of EDTA. The angioplasty group had unmodified reperfusion by simple release of the occlusion. The area at risk and the area infarcted were estimated with Evans blue and triphgnyl tetrazolium hydiochloride stains, respectively. The ratio of the area infarcted to the area at risk was significantly lower with Trolox (angioplasty, 33.4% \ub1 5.1%; saline, 20.8% \ub1 2.9%; and Trolox, 8.7% \ub1 4.0%; p < 0.01). In summary, the antioxidants Trolox and ascorbic acid effectively reduced myocardial necrosis after ischemia. \ua9 1989.Peer reviewed: YesNRC publication: Ye