Developmental exposure to a human-relevant PCB mixture: impacts on PCB congeners, metabolites, and drug-metabolizing enzymes in the bladder of post-weaning mice

Many women suffer from symptoms associated with dysfunction of the lower urinary tract, including incontinence and overactive bladder, especially during pregnancy. While causes are likely multifactorial, environmental factors, such as exposure to polychlorinated biphenyls (PCBs), have been shown to alter voiding in adult female mice. However, the distribution of PCBs and their metabolites to the bladder and urine, as well as their effects on bladder drug-metabolizing enzyme expression after dosing with PCB mixtures, remains largely unexplored. Female C57BL/6J mice were exposed to MARBLES PCB mixture (0, 0.1, 1, and 6 mg/kg/d) through gestation and lactation, and post-weaning bladder, urine, blood, adipose, and liver were collected for measurement of PCBs and OH-PCBs, and for abundance of cytochrome P450 (Cyp) transcripts in liver and bladder. PCBs and OH-PCBs were detected in all tissues in a dose-dependent manner. Bladder, adipose, and liver retained parent PCBs while OH-PCBs were predominant in urine and blood. Cyp1a2 mRNA abundance was elevated in the liver of the high dose PCB group versus the vehicle, and the same trend was observed in the bladder. These results define the signatures of PCBs and OH-PCBs in the bladders and urine of post-weaning dams exposed to the MARBLES mixture of PCBs and provide a reference for comparison with accumulation in more commonly studied tissues. Our results also provide new insights into the regulation of Cyp1a2 in the liver and bladder, changes that may play a role in how environmental exposures in adulthood alter voiding function.