Coordinated Changes in Xenobiotic Metabolizing Enzyme Gene Expression in Aging Male Rats: Brown Norway and F344

In order to gain insight into the effects of aging on susceptibility to environmental toxins, we characterized the expression of xenobiotic metabolizing enzymes (XMEs) from the livers of male Brown Norway and F344 rats across the adult lifespan. To examine metabolic processes across lifespan after challenge with a xenobiotic compound, Brown Norway rats were exposed to 1.0 g/kg body weight toluene by oral gavage in corn oil (4ml/kg body weight) or corn oil alone. Keywords: age effect on toxin susceptibility Brown Norway rats: Analysis of gene expression profiles for XMEs in male Brown Norway rats 4, 12, and 24 months old. Rats were exposed to 1g/kg toluene by oral gavage, and sacrificed after 4 hours. Total RNA was isolated from liver samples and gene expression analyzed using Affymetrix Rat 230 2.0 full-genome GeneChips. Data from 18 samples, with three rats in each of the control age groups and dosed age groups, were analyzed. F344 rats: Analysis of gene expression profiles for XMEs in male F344 6, 11, 18, and 24 months old. Total RNA was isolated from liver samples and gene expression analyzed using Affymetrix Rat 230 2.0 full-genome GeneChips. Data from 16 samples, with four rats in each of the 4 age groups, were analyzed.