Accumulation, elimination, and effects of parenteral exposure to aluminum in newborn and adult rats

• Parenteral aluminum does not impair cognitive functions in newborn rats.
• Tissue aluminum accumulation in newborn is higher than in adult rats.
• Tissue aluminum elimination rate in newborn is higher than in adult rats.

Aluminum (Al) delivered to preterm infants via parenteral nutrition may exceed the limit of 5 μg/kg/day set by the US Food and Drug Administration. This study evaluated the effect of the administration of an equivalent amount of Al (0.12 mg/kg/day) to newborn rats. The study included the administration of a higher amount of Al (24.8 mg/kg/day) not only to newborn rats but also to adult (2- and 4-month-old) rats. Aluminum was intraperitoneally administered for a period of 10 days. Newborn animals were evaluated for developmental changes every day starting from the second day after birth. Twenty days after the last administration, 10 animals were killed and their organs were removed; the remainders were killed on day 40. A dosage of 24.8 mg/kg/day was administered to the two groups of adult rats, which were killed following the same protocol after 20 and 40 days. The results of physical parameters and developmental and behavioral tests were not conclusive and no significant differences were observed between the lower and higher Al dose and control groups. The group that received 0.12 mg/kg/day showed significant differences in Al accumulation only in the liver and muscle. The groups that received a higher dose of Al showed an accumulation in all tissues among all age groups studied, but the newborn group showed the greatest accumulation (results for day 20). After 40 days, Al content in all tissues decreased more than 50% in this group, whereas among the adults, the Al content increased or remained constant. An increase in age correlated with a lower elimination rate. Considering the ongoing human Al exposure, along with its age-related elimination rate, Al accumulation in the body may be long-lasting.

Evolution of tissue aluminum deposition as a function of age in newborn (NB), 2-month (2-mo), and 4-month old rats (4-mo), before aluminum administration and after 20 and 40 days of the end of exposure.Figure optionsDownload as PowerPoint slide