The effect of lead and polychlorinated biphenyl exposure on rat natural killer cell cytotoxicity

摘要: Splenic natural killer (NK) cell cytotoxicity was assessed in rats chronically exposed to lead (Pb) as acetate the drinking water or polychlorinated biphenyl (PCB) Aroclor 1254 feed. Rats treated with cyclophosphamide were included positive immunosuppressed controls. Weanling, male Sprague-Dawley 50 and 500 ppm PCB feed for ten weeks exhibited significantly suppressed (P<0.01) splenic NK activity. Cyclophosphamide injected i.p. six days prior termination at a dose of 75 mg/kg also inhibited activity reduced, though not significantly, spleen cells isolated from animals 10 1000 Pb weeks. In vitro exposure rat concentrations 0.4 20.0 μg/ml similarly resulted significant depression addition, same splenocytes. These results indicate that two environmental contaminants have ability adversely affect cytotoxicity. The effects seen here on may part explain tumor inducing effect these chemicals are suspected possessing via compromising immune surveillance system.