Manganese-nickel interaction in a tracheal ring model system.

The effects of NiCl2 and MnCl2 on the ciliary activity in mouse trachea were observed in an organ culture system. Following exposure for 2 hours to NiCl2 (0.5 or 2.0 mM) in Medium 199 40 respectively 0% of the ciliary activity remained. By simultaneous exposure to increasing concentrations of MnCl2 the toxic effect of NiCl2 was reduced and the ciliary activity following 2 hours incubation in the presence of 0.5 or 2.0 mM NiCl2 was 81 and 62%. At these nickel-concentrations optimal protection was obtained by about half the molar concentration of MnCl2. Preincubation in medium supplemented with NiCl2 followed by incubation in medium with MnCl2 added gave better protection than that obtained by changing to Medium 199 alone. Preincubation in 0.25 mM MnCl2 did not reduce nickel toxicity.