Toxicity of gestational aluminum exposure to the maternal rabbit and offspring

To assess aluminum toxicity to the Al-exposed pregnant female and her developing offspring, pregnant rabbits received 20 sc Al lactate injections (0, 25, 100, or 400 mumol Al/kg/inj) between Days 2 and 27 of gestation. Fifty-eight percent perinatal mortality resulted from the highest dose. At 2 days postpartum litters were culled to six offspring. Three of the offspring of Al-treated does were cross-fostered to a non-Al-treated doe in exchange for three of the non-Al-treated doe's offspring. Tissue Al concentrations in 0- to 2-day-old offspring positively correlated with their does' Al exposure, but were lower than Al concentrations in placental tissue or in does 5 weeks postpartum, suggesting that the placenta partially protects the fetus from Al. Offspring of 25 mumol group does gained body weight faster than controls, whereas 400 mumol group does and their offspring gained weight less rapidly than controls. The weight of milk consumed by offspring inversely correlated with their does' Al exposure. Learning a classically conditioned reflex was facilitated by lower and impaired by higher Al exposure in offspring conditioned at 7 and 11 weeks of age. Offspring receiving higher Al exposure also showed impaired memory of the learned reflex. Aluminum appears to distribute into the developing fetus where it accumulates and can produce delayed effects which may be beneficial following lower but detrimental following higher exposure concentrations.