Shrivastava Richa, Upreti R K, Chaturvedi U C
Biomembrane Division, Industrial Toxicology Research Centre, Mahatma Gandhi Marg, 226001 Lucknow, India.
FEMS Immunol Med Microbiol. 2003 Aug 18;38(1):65-70. doi: 10.1016/S0928-8244(03)00107-X.
The cells of the immune system form a strong line of defence against foreign substances. The present study was undertaken to investigate the capacity of different cells of Wistar rats to reduce potentially carcinogenic hexavalent chromium (Cr-VI) into less toxic trivalent chromium in vitro. 5 x 10(6) cells were incubated with 10 or 25 microg ml(-1) of Cr (VI) in the form of K2Cr2O7 at 37 degrees C in the presence of 5% CO2 in air. At various time periods the remaining amount of Cr (VI) was measured and the percentage of Cr (VI) reduced was calculated. Among the single cell suspensions from the splenic cells a peak reduction of 55% was observed with the total spleen cells, 40% with the B-lymphocyte-enriched subpopulation, 10% with T-lymphocytes and 24% with the macrophages. The reduction by splenic and peritoneal macrophages was similar. Total thymocytes reduced 54% of the Cr (VI). Since the most common route of entry of chromium is through drinking water and food, intestinal cells were also investigated. Among the intestinal cells the maximum reduction of 100% (of 10 microg ml(-1)) was observed with the upper villus cells and 72% with the middle villus cells while reduction was the least (4%) with the crypt cells. The reduction in the intestinal loop in situ was 100%. The time taken by each cell type for the peak reduction to Cr (VI) was markedly different. The findings thus show that the capacity of different cells in the body differs vastly in their capacity and time taken to reduce hexavalent chromium. The most efficient handling of Cr (VI) by the intestine, due to the presence of a variety of cells and bacteria, protects the body from its adverse effects.
免疫系统的细胞对外来物质形成了强大的防御线。本研究旨在调查Wistar大鼠不同细胞在体外将潜在致癌的六价铬（Cr-VI）还原为毒性较小的三价铬的能力。将5×10⁶个细胞与10或25微克/毫升以重铬酸钾形式存在的Cr（VI）在37℃、空气中含5%二氧化碳的条件下孵育。在不同时间段测量剩余的Cr（VI）量，并计算Cr（VI）还原的百分比。在脾细胞的单细胞悬液中，观察到总脾细胞对Cr（VI）的还原峰值为55%，富含B淋巴细胞的亚群为40%，T淋巴细胞为10%，巨噬细胞为24%。脾巨噬细胞和腹腔巨噬细胞的还原情况相似。总胸腺细胞还原了54%的Cr（VI）。由于铬最常见的进入途径是通过饮用水和食物，因此也对肠道细胞进行了研究。在肠道细胞中，观察到上绒毛细胞对10微克/毫升Cr（VI）的最大还原率为100%，中绒毛细胞为72%，而隐窝细胞的还原率最低（4%）。肠道原位环的还原率为100%。每种细胞类型将Cr（VI）还原至峰值所需的时间明显不同。因此，研究结果表明，体内不同细胞还原六价铬的能力和所需时间差异很大。由于存在多种细胞和细菌，肠道对Cr（VI）的处理最为有效，可保护身体免受其不良影响。
