Antibody forming cell response to nickel and nickel-coated fly ash in rats.

The potential of nickel as nickel chloride, native fly ash and Ni-coated fly ash to alter pulmonary and systemic immune response was evaluated upon intratracheal (I/T) exposure of rats. The animals were sensitised with sheep red blood cells (SRBC) through I/T and intraperitoneal (I/P) routes. Nickel exposure resulted in a decrease in the number of antibody forming cells (AFC) in lung associated lymph nodes (LALN) and spleen. In rats exposed to native fly ash there was a reduction in the number of AFC in LALN but not in spleen. The results did not demonstrate any significant difference in the immunosuppression of fly ash and Ni-coated fly ash exposed rats. The decrease in AFC formation in Ni-coated fly ash exposed animals was of a lesser magnitude than in rats exposed to Ni-alone.