SHORT-TERM CHANGES IN ERYTHROCYTE ALPHA-TOCOPHEROL CONTENT OF VITAMIN-E-DEFICIENT PATIENTS WITH CYSTIC-FIBROSIS

Polyunsaturated fatty acids of biomembranes are a major target of lipid peroxidation. In vitamin E deficiency an efficient delivery of a high oral loading dose of all-rac-alpha-tocopheryl acetate to erythrocyte membranes could provide an early onset antioxidative effect. We investigated short-term changes in erythrocyte alpha-tocopherol after a single oral dose of 100 mg all-rac-alpha-tocopheryl acetate/kg in 10 vitamin E-deficient cystic fibrosis (CF) patients. Over 24 h, erythrocyte alpha-tocopherol increased 68% to 420% of preloading concentrations. With two exceptions, peak values were achieved 12 or 24 h after administration, which was 3-18 h later than peak plasma concentrations. Separate median-based curve estimates for the changes in erythrocyte alpha-tocopherol for five patients with and five without associated cholestatic liver disease were obtained. Cross-sectional test results revealed significantly lower erythrocyte alpha-tocopherol for the 9- and 24-h observations for patients with cholestatic liver disease compared with those without. Oral all-rac-alpha-tocopheryl acetate can be rapidly incorporated into erythrocyte membranes in vitamin E-deficient CF patients.