Evaluation of the reproductive toxicity of gallium nitrate in mice.

Reproduction studies were performed with gallium nitrate, an antihypercalcaemic drug that is also used as a chemotherapeutic agent for the treatment of certain malignancies. Male mice were injected subcutaneously with gallium nitrate at doses of 0 (controls), 24, 48 and 96 mg/kg/day every other day for 14 days before mating with untreated females. Fertility and reproductive performance in the gallium nitrate-treated groups did not differ significantly from controls. No significant changes were observed in the relative testes and epididymis weights. Sperm counts in the gallium nitrate-dosed groups were comparable with those in the control group, whereas the percentage of motile cells was similar between treated and untreated animals. Histopathological examination of the testes and epididymis did not reveal any changes at any dose of gallium nitrate. The no-observed-adverse effect level was 96 mg/kg body weight. This dose is about 30 times higher than the current doses of gallium nitrate administered to humans.