Thoracic aortae, isolated from rats supplemented with dietary vitamin E after vitamin E deficiency, were analysed for changes in vascular reactivity. 2. Following 4 or 12 months of dietary vitamin E deficiency, endothelium-dependent vasodilator responses to acetylcholine were significantly impaired. However, when animals were fed after the first 4 months of vitamin E deprivation with a vitamin E-supplemented diet for 8 months, endothelium-mediated responses were completely restored. 3. In contrast, the endothelium-independent vasodilator or vasoconstrictor responses to sodium nitroprusside and noradrenaline, respectively were not altered either by vitamin E deficiency or supplementation. 4. These data indicate that vitamin E supplementation reversed the impairment of endothelial cell function which occurs during vitamin E deficiency.
