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, whether orally administered alpha-tocopheryl acetate was effective in increasing myocardial alpha-tocopherol levels and 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 preoperatively 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 nondeuterated alpha-tocopherol levels were measured by gas chromatography/mass spectrometry. Although there was a decrease (p less than 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.
Mickle
D A
DA
Department of Clinical Biochemistry, Toronto General Hospital, University of Toronto, Ontario, Canada.
Weisel
R D
RD
Burton
G W
GW
Ingold
K U
KU
D000284:Administration, Oral; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D006801:Humans; D015425:Myocardial Reperfusion / Q000009:adverse effects*; D009206:Myocardium / Q000378:metabolism*; D011300:Preoperative Care / Q000379:methods*; D024505:Tocopherols; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000627:therapeutic use; D024502:alpha-Tocopherol / Q000031:analogs & derivatives*
D014810:Vitamin E; D024502:alpha-Tocopherol; D024505:Tocopherols