Developmental toxicity of vanadium in mice after oral administration.

Vanadium, as vanadyl sulphate pentahydrate, was evaluated for its embryotoxic, fetotoxic and teratogenic potential in Swiss mice. The compound was administered by gavage to pregnant mice at doses of 0, 37.5, 75 or 150 mg kg-1 day-1 on days 6-15 of pregnancy. On gestation day 18, all live fetuses were examined for external, visceral and skeletal malformations and variations. Maternal toxicity was observed in the vanadium-treated animals, as evidenced by reduced weight gain, reduced body weight on gestation day 18 (corrected for gravid uterine weight) and decreased absolute liver and kidney weights at 75 and 150 mg kg-1 day-1. The number of total implants, live and dead fetuses, late resorptions, the sex ratio and the post-implantation losses were not significantly different between the vanadium-treated mice and the controls. However, there was a significant increase in the number of early resorptions per litter at all dose levels. Fetotoxicity was evidenced by lower fetal weights and fetal lengths, and the presence of developmental variations. Malformation incidence also was increased by the administration of vanadium. Thus, the 'no observable effect level' (NOEL) for maternal toxicity, embryofetotoxicity and teratogenicity for vanadyl sulphate pentahydrate under these test conditions was below 37.5 mg kg-1 day-1 for Swiss mice.