A new study indicates that primates exposed to lead as infants show Alzheimer disease–like pathology later (Wu J et al. J Neurosci. 2008;28[1]:3-9).
A research team led by investigators at the University of Rhode Island in Kingston exposed Macaca fascicularis monkeys from birth to age 400 days to lead levels that produced no obvious sign of toxicity. After approximately 23 years, examination of the brains of the lead-exposed monkeys revealed many hallmarks of Alzheimer disease despite undetectable levels of lead in the blood. Brains of these monkeys harbored neuronal plaques and neurofibrillary tangles and exhibited increased expression of Alzheimer disease–related genes.
The team also found a decrease in DNA methyltransferase activity and higher oxidative damage to DNA in the brains of lead-exposed monkeys.
The study indicates that lead exposure early in life may predispose animals to later neurodegenerative disease, possibly through alterations in DNA methylation and . . . [Full Text of this Article]