Superfund Research Program
PCB Effects on Uterine Muscle
Project Leader: Rita Loch-Caruso (University of Michigan)
Grant Number: P42ES004911
Funding Period: 1995 - 2006
Previous epidemiological and laboratory animal studies indicate that some polychlorinated biphenyls (PCBs) alter the length of gestation. Because parturition requires forceful oscillatory uterine contractions, this project is investigating how PCBs alter uterine muscle contraction. The current studies showed that removal of chlorines by anaerobic biodegradation produced PCB mixtures with increased stimulatory activity in the uterus compared with the parent non-dechlorinated mixtures. Dichlorobiphenyls with ortho substitution of one phenyl ring stimulated contraction frequency if the other ring had a chlorine at the ortho or para position, whereas 4,4'-dichlorobiphenyl had no significant effect on oscillatory uterine contractions. Additional studies showed that 2,2'-dichlorobiphenyl promoted desynchronization of uterine contractions, possibly by an oxidative stress-mediated mechanism. The results from these experiments may provide a scientific basis for previous reports that PCBs alter parturition.