Lead-exposure of neonatal rats through maternal milk : A confounded model

Protective effects of selenium to placental lead neurotoxicity in rat pups

The neurotoxic effects of lead are age-related phenomena, which in turn are dependent on nutrition status as well as the presence of other micronutrients. The present study was designed to study the protective effects of selenium on rat pups exposed to lead. The activities of different enzymes in cerebrum and cerebellum regions were estimated following maternal lead neurotoxicity through placenta. The parental animals were exposed to different treatments for 5 weeks prior to gestation and 3 weeks during gestation; that is, animals were exposed for a total period of 8 weeks and rat pups obtained from exposed parents were allowed to survive on their mothers' milk for a period of 1 month, after which they were sacrificed. Activities of succinic dehydrogenase (SDH), acetylcholine estrase (AChE), and Na(+)/K(+)-ATPase were studied in the cerebrum and cerebellum of the rat pups at 4 weeks of age. A significant reduction in the activity of all the three enzymes-SDH, AChE and Na(+)/K(+) -ATPase-was observed in the lead-treated group, except in the case of AChE, which increased in the case of cerebrum. However, changes in different enzyme activities were less pronounced in the animals that were treated simultaneously with selenium and lead. No pups were delivered to the mothers who were exposed to selenium alone for period of 8 weeks.

Aluminum transfer through milk in female rats intoxicated by aluminum chloride

Female rats received an ip injection of aluminum chloride (10 mg Al/kg/d) during the first 12 d after parturition; this treatment led to a reduction in food intake associated with a reduction in body wt. Pups of the intoxicated dams showed a growth retardation after postnatal day 7. One day after treatment, the female rats intoxicated with aluminum had a considerably higher level of aluminum in milk than controls. The aluminum levels of plasma, liver, spleen, and kidneys were also significantly higher in treated female rats than controls. On the contrary, in the same tissues of pups from treated or not treated dams, no differences in aluminum levels were observed. No effect of aluminum treatment was detected on plasma silicon levels in dams and pups.