Mobilization of nickel by potassium ethylxanthate in mice: comparison with sodium diethyldithiocarbamate and effect of intravenous versus oral administration.

Intravenous administration of 63Ni2+ (as 63NiCl2) together with potassium ethylxanthate resulted in highly increased levels of 63Ni2+ in several tissues of mice in comparison with animals given 63Ni2+ alone. However, this effect was not observed when 63Ni2+ and potassium ethylxanthate were given orally. Sodium diethyldithiocarbamate was active in increasing 63Ni2+ concentrations after both intravenous and oral administration. Both ethylxanthate and diethyldithiocarbamate can form highly lipophilic complexes with nickel and a facilitated penetration of these complexes through the cellular membranes of the tissues probably explains the increased uptake of the metal. Xanthates are unstable at acid pH and degradation in the acid milieu of the stomach probably underlies the lack of effect at oral administration.