Zinc: an overview.
Zinc: an overview.
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作者：
A. Prasad
人类缺锌在世界范围内普遍存在。在人们以谷物蛋白为生的地区，这种情况更为普遍。条件性锌缺乏可见于许多疾病状态。在生长期缺乏它会导致男性生长障碍和性腺发育不足。缺锌的其他影响包括皮肤变化、食欲不振、精神萎靡、伤口愈合延迟、神经感觉障碍和细胞介导的免疫障碍。严重的锌缺乏，如肠病性肢端皮炎（一种遗传性疾病），如果不给这些患者补充锌，就会致命。人类边缘性锌缺乏的临床诊断仍然存在问题。与血浆锌相比，粒细胞和淋巴细胞中锌的测定为边缘性锌缺乏提供了更好的诊断标准。已知大约 300 种酶的活性需要锌。 DNA 合成、细胞分裂和蛋白质合成都需要锌。最近，我们了解到锌指蛋白参与各种生长因子和类固醇受体的基因表达。我们怀疑数百种含锌核蛋白可能参与各种蛋白质的基因表达。锌缺乏会对淋巴细胞增殖产生不利影响。这可能与 Zn 在 DNA 合成和细胞分裂中的酶促作用有关。胸腺素是一种参与 T 淋巴细胞成熟的胸腺激素，已知它具有锌依赖性，并且会受到锌缺乏的不利影响。因此，缺锌也可能对淋巴细胞的分化和成熟产生不利影响。已知缺锌会减少辅助 T 淋巴细胞产生白细胞介素 2，并且在缺锌人类中观察到 T 淋巴细胞亚群异常。（摘要截短为 250 字）
Zn deficiency in humans is widespread throughout the world. It is more prevalent in areas where the population subsists on cereal proteins. Conditioned Zn deficiency is seen in many disease states. Its deficiency during growth periods results in growth failure and lack of gonadal development in males. Other effects of Zn deficiency include skin changes, poor appetite, mental lethargy, delayed wound healing, neurosensory disorders, and cell-mediated immune disorders. Severe Zn deficiency, as seen in acrodermatitis enteropathica (a genetic disorder), is fatal if Zn is not administered to these patients. A clinical diagnosis of marginal Zn deficiency in humans remains problematic. Assays of Zn in granulocytes and lymphocytes provide better diagnostic criteria for marginal Zn deficiency than plasma Zn. Approximately 300 enzymes are known to require Zn for their activities. Zn is required for DNA synthesis, cell division, and protein synthesis. Recently, we learned that Zn-finger proteins are involved in genetic expression of various growth factors and steroid receptors. We suspect that several hundred Zn-containing nucleoproteins are probably involved in gene expression of various proteins. Zn deficiency adversely affects lymphocyte proliferation. This may be related to the enzymatic role of Zn in DNA synthesis and cell division. Thymulin, a thymic hormone involved in T-lymphocyte maturation, is known to be Zn dependent and is adversely affected by Zn deficiency. Thus, an adverse effect of Zn deficiency may also be in lymphocyte differentiation and maturity. Zn deficiency is known to decrease interleukin 2 production by helper T lymphocytes, and abnormalities in T-lymphocyte subpopulations have been observed in Zn-deficient humans.(ABSTRACT TRUNCATED AT 250 WORDS)