Umegaki K, Aoki S, Esashi T
Division of Applied Food Research, National Institute of Health and Nutrition, Tokyo, Japan.
Free Radic Biol Med. 1995 Oct;19(4):493-7. doi: 10.1016/0891-5849(95)00033-t.
The change in the ascorbic acid concentration in the bone marrow after whole body X-ray irradiation was compared with that in the vitamin E concentration. The ascorbic acid concentration in the bone marrow significantly decreased by 30% 1 h after exposure to 3 Gy of X-rays, whereas the vitamin E concentration in the bone marrow was significantly decreased 5 h after exposure, when the level of ascorbic acid was less than 10% of that in the control. At 24 h after exposure, the ascorbic acid concentration in the bone marrow was significantly decreased by 80% after exposure to 0.5 Gy, whereas the vitamin E concentration was significantly decreased after exposure to 1 Gy or more. In the bone marrow, the decrease in the ascorbic acid concentration was accompanied by a marked increase in the concentration of dehydroascorbic acid, an oxidized form of ascorbic acid. X-ray irradiation did not decrease either the ascorbic acid or vitamin E concentration in the serum or intestine. These findings suggest that the bone marrow is more highly susceptible to oxidative damage by radiation and that ascorbic acid plays an important defense role against it. On Day 8 after irradiation, the decreases in the vitamin E and ascorbic acid concentrations in the bone marrow showed recovery after exposure to 3 Gy, but not after the exposure to 6 Gy.
将全身X射线照射后骨髓中抗坏血酸浓度的变化与维生素E浓度的变化进行了比较。暴露于3 Gy X射线后1小时，骨髓中的抗坏血酸浓度显著降低了30%，而骨髓中的维生素E浓度在暴露后5小时显著降低，此时抗坏血酸水平低于对照组的10%。暴露后24小时，暴露于0.5 Gy后骨髓中的抗坏血酸浓度显著降低了80%，而暴露于1 Gy或更高剂量后维生素E浓度显著降低。在骨髓中，抗坏血酸浓度的降低伴随着抗坏血酸氧化形式脱氢抗坏血酸浓度的显著增加。X射线照射并未降低血清或肠道中的抗坏血酸或维生素E浓度。这些发现表明，骨髓对辐射的氧化损伤更敏感，抗坏血酸对其起着重要的防御作用。照射后第8天，暴露于3 Gy后骨髓中维生素E和抗坏血酸浓度的降低显示出恢复，但暴露于6 Gy后未恢复。
