Abdallah S M, Samman S
Department of Biochemistry, University of Sydney, NSW, Australia.
Eur J Clin Nutr. 1993 May;47(5):327-32.
Zinc has many diverse functions and is essential for growth and development. Although a number of dietary constituents inhibit its absorption, a reliable index of zinc intake and/or bioavailability remains to be identified. The aim of this study was to test the hypothesis that recent changes in zinc intake and/or bioavailability are reflected in a subfraction of erythrocytes. Six healthy female volunteers were asked to supplement their diet with 50 mg of elemental zinc per day for 12 days. Venous blood samples were obtained before and during supplementation at 4-day intervals. A subfraction of erythrocytes was isolated from each sample and zinc concentration was measured in this subfraction, in the unfractionated erythrocytes and in the plasma. These showed no significant temporal change. Erythrocyte superoxide dismutase (E-SOD), a marker of copper status, showed a significant 20% decrease (P < 0.02) in its activity in both the subfraction and the unfractionated erythrocytes following supplementation. Hence, a detrimental effect on copper metabolism (as measured by the marker enzyme E-SOD) can be detected within 12 days of supplementation with a moderate amount of zinc.
锌具有多种不同功能，对生长发育至关重要。尽管许多膳食成分会抑制其吸收，但锌摄入量和/或生物利用度的可靠指标仍有待确定。本研究的目的是检验以下假设：红细胞亚组分能反映锌摄入量和/或生物利用度的近期变化。六名健康女性志愿者被要求每天在饮食中补充50毫克元素锌，持续12天。在补充前和补充期间，每隔4天采集静脉血样。从每个样本中分离出红细胞亚组分，并测量该亚组分、未分离的红细胞和血浆中的锌浓度。这些结果显示没有明显的时间变化。红细胞超氧化物歧化酶（E-SOD）是铜状态的标志物，补充后其在亚组分和未分离的红细胞中的活性均显著降低了20%（P < 0.02）。因此，在补充适量锌的12天内，可检测到对铜代谢（以标志物酶E-SOD衡量）的有害影响。
