Investigations on animals gave some more data on the effects
of this mixture on oxidative stress parameters. In a study conducted
on female rats during their pregnancy to parturition or until
weaning, Pb-acetate and/or Cd-acetate were administrated via drinking
water at concentrations of 300 mg/L and 10 mg/L, respectively
(Massó et al., 2007). Blood levels of the metals in the dams were
significantly increased in experimental groups treated with one toxic
metal only (if compared to controls) while co-exposure resulted in
diminished levels of both Pb and Cd in comparison to the groups
exposed to a single metal. Although the authors did not investigate
parameters of oxidative stress in blood of treated dams, lower
levels of these metals observed in co-exposed group suggest a possible
antagonistic effect of these metals when applied orally due to
interactions at the level of the gastrointestinal tract, possibly because
of different affinity of these metals for binding to protein transporters,
DMT 1 transporter being the most important one.