Suzuki Y
Department of Occupational Diseases, National Institute of Industrial Health, Kawasaki, Japan.
Arch Toxicol. 1988;62(2-3):116-22. doi: 10.1007/BF00570129.
The reduction of hexavalent chromium [chromium(VI)] in lung lavage fluids, microsomal (S-9) fractions of lung and liver tissues, erythrocyte lysates and plasma prepared from adult rats was examined at pH 7.4 (37 degrees C). Specific reducing capacity, which was defined as the amount of chromium(VI) reduced per mg of protein in the test sample, was highest in the lavage fluids. The concomitant trivalent species [chromium(III)] was detected as complexes with some of the lavage components and probably as colloidal hydroxides. By gel filtration analysis and UV spectrometry, ascorbic acid (AsA) was identified as an important reducing factor in the lavage fluids. AsA levels in the lavage fluids were about 38 micrograms/g tissue, corresponding to 12% of total AsA in the intact lungs. The molar ratios of oxidized AsA and reduced chromium(VI) in the lavage samples were about 3:2.3 on an average. On the basis of this molar ratio, the AsA levels in the lavage fluids are equivalent to a reducing capacity of 8.4 micrograms chromium(VI)/g tissue. These results suggest that the lining layers (surfactant layers) of rat lungs provide an AsA-related capacity for protection of the cells against the toxic effects of chromates and probably other oxidants.
在pH 7.4（37℃）条件下，对成年大鼠肺灌洗液、肺和肝组织的微粒体（S-9）组分、红细胞裂解物及血浆中六价铬[铬（VI）]的还原情况进行了检测。比还原能力定义为测试样品中每毫克蛋白质还原铬（VI）的量，其在灌洗液中最高。伴随产生的三价铬[铬（III）]被检测为与某些灌洗成分形成的络合物，可能还有胶体氢氧化铬。通过凝胶过滤分析和紫外光谱法，已确定灌洗液中的抗坏血酸（AsA）是一种重要的还原因子。灌洗液中的AsA水平约为38微克/克组织，相当于完整肺组织中总AsA的12%。灌洗样品中氧化型AsA与还原型铬（VI）的摩尔比平均约为3:2.3。基于该摩尔比，灌洗液中的AsA水平相当于8.4微克铬（VI）/克组织的还原能力。这些结果表明，大鼠肺的内衬层（表面活性剂层）具有与AsA相关的能力，可保护细胞免受铬酸盐及可能其他氧化剂的毒性作用。
