Talcott P A, Koller L D, Exon J H
Int J Immunopharmacol. 1985;7(2):255-61. doi: 10.1016/0192-0561(85)90034-7.
Splenic natural killer (NK) cell cytotoxicity was assessed in rats chronically exposed to lead (Pb) as lead acetate in the drinking water or polychlorinated biphenyl (PCB) as Aroclor 1254 in the feed. Rats treated with cyclophosphamide were included as positive immunosuppressed controls. Weanling, male Sprague-Dawley rats exposed to 50 and 500 ppm PCB in the feed for ten weeks exhibited significantly suppressed (P less than 0.01) splenic NK activity. Cyclophosphamide injected i.p. six days prior to termination at a dose of 75 mg/kg also significantly inhibited splenic NK activity. NK cell activity was reduced, though not significantly, in spleen cells isolated from animals exposed to 10 and 1000 ppm Pb as Pb acetate in the drinking water for ten weeks. In vitro exposure of rat spleen cells to PCB at concentrations of 0.4 and 20.0 micrograms/ml similarly resulted in a significant depression of splenic NK cell activity. In addition, in vitro exposure to lead at the same concentrations resulted in suppressed NK cell cytotoxicity of rat splenocytes. These results indicate that two environmental contaminants have the ability to adversely affect NK cell cytotoxicity. The effects seen here with Pb and PCB on NK cells may in part explain the tumor inducing effect these chemicals are suspected of possessing via compromising the immune surveillance system.
通过在饮水中添加醋酸铅使大鼠长期接触铅（Pb），或在饲料中添加多氯联苯（PCB）商品名Aroclor 1254使大鼠长期接触多氯联苯，以此评估大鼠脾脏自然杀伤（NK）细胞的细胞毒性。用环磷酰胺处理的大鼠作为免疫抑制阳性对照。断奶的雄性Sprague-Dawley大鼠在饲料中接触50 ppm和500 ppm的多氯联苯，持续十周，其脾脏NK活性显著受到抑制（P小于0.01）。在处死前六天腹腔注射剂量为75 mg/kg的环磷酰胺，也显著抑制了脾脏NK活性。从饮水中摄入10 ppm和1000 ppm醋酸铅的大鼠，持续十周，从其分离得到的脾细胞中NK细胞活性有所降低，但并不显著。将大鼠脾细胞在体外暴露于浓度为0.4 μg/ml和20.0 μg/ml的多氯联苯中，同样导致脾脏NK细胞活性显著降低。此外，在体外暴露于相同浓度的铅，也会抑制大鼠脾细胞的NK细胞细胞毒性。这些结果表明，两种环境污染物都有能力对NK细胞细胞毒性产生不利影响。此处观察到的铅和多氯联苯对NK细胞的影响，可能部分解释了这些化学物质被怀疑通过损害免疫监视系统而具有的肿瘤诱导作用。
