[Transplacental passage of vanadium after treatment with vanadium pentoxide in Wistar rat].

The passage of vanadium pentoxide across the placenta into the embryo/fetus was investigated by analyzing the vanadium content in embryo/fetus at various intervals between 1 h and 48 h after treatment of pregnant Wistar rats with single dose of the V2O5 (5mg/kg) on days 16-18 of gestation, at 4h after treatment of pregnant rats with single dose of V2O5 (5mg/kg) on day 12, and at 120 h after treatment of pregnant rats with dose of V2O5 0.33, 1.0, 3.0 mg/kg on days 6 through 15. The V concentration was determined by catalytic polarography. At after treatment on day 12, the V concentrations in maternal blood, placenta and embryos were elevated in comparison with those of the untreated group. At 4-48 h after treatment on days 16-18, the V concentrations in placenta and fetuses were elevated in comparison with those of the untreated group. The V concentration at 4 h after treatment in various tissues is the highest one among different time points. On days 16-18, 4 h after treatment, the V concentration in placenta was elevated in comparison with that on day 12 of gestation, but the V concentration in embryo/fetus was decreased. At 120 h after treatment on days 6-15, the V concentration in fetus is still high in comparison with that of the untreated group. The V content of fetus varied according to doses, suggesting that embryo/fetus accumulates vanadium. The results showed that vanadium can pass through the placental barrier and enter the embryo/fetus during the embryonal organogenesis in rat, but placenta accumulates vanadium, and the barrier action increases with placental maturity.