Superfund Research Program
PCB Effects on Uterine Muscle
Project Leader: Rita Loch-Caruso (University of Michigan)
Grant Number: P42ES004911
Funding Period: 1995 - 2006
Research within this project currently focuses on the risks to maternal and fetal health of exposure to polychlorinated biphenyls (PCBs), which have been observed to alter the uterine muscle functions involved in labor. Studies with laboratory animals, wildlife, and human populations suggest that PCBs alter the length of gestation and modify labor. Researchers in this project have found that PCBs exert a myriad of effects on uterine muscle. When PCB congeners are applied to isolated segments of uterus in an organ bath, uterine contractions may be stimulated, inhibited, or unaffected, depending on the structure of the particular PCB. Humans are typically exposed to mixtures of PCBs, and PCB mixtures with different chlorine content (Aroclor 1242, 1248, and 1254) stimulate uterine contractions. For both mixtures and individual congeners, PCBs with lower chlorine content exert the greatest activity on the uterus. Experiments with uterine muscle cells in culture indicate that Aroclor 1242 increases intracellular calcium and activates phospholipid cell signaling pathways. Further experiments with isolated uterine segments suggest that activation of the phospholipid cell signalling pathways may mediate PCB stimulation of uterine contraction. These findings may have implications for clean-up strategies of PCB contaminated Superfund sites, providing insight into possible risks to pregnancy that may arise from PCB degradation to more lightly chlorinated species.