title: Effect of an environmentally relevant metabolized organochlorine mixture on porcine cumulus-oocyte complexes.
abstract: Organochlorine compounds and their metabolites bioaccumulate and have been detected in follicular and genital tract fluids of humans and animals. This study was designed to investigate the effect of a metabolised organochlorine mixture, extracted from plasma of sows treated with an environmentally relevant organochlorine mixture in the course of a previous study, on porcine cumulus-oocyte complexes (COCs) in vitro. The major component of the metabolised mixture is 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (p,p'-DDE) at 15.1 mg/l, which accounts for 40.7% of the total extract. Polychlorinated biphenyls (PCBs) account for 30.8% of the extract and hydroxylated PCB metabolites (OH-PCBs) for 11.8%. Exposure of COCs to the metabolised mixture induced a decrease of apoptotic cumulus cells at low concentrations and an increase at higher concentrations following a U-shaped curve (p=0.0106), with the intermediate treatment (3.6 microg/l OH-PCBs) significantly reducing apoptosis compared to the extraction control (p=0.05). However, the metabolised mixture did not affect cumulus expansion, oocyte maturation, penetration, development to blastocyst, or the number of cells per blastocyst. This study also indicates that organochlorine metabolites similar in concentrations to levels found in Arctic populations can affect growing cumulus-oocyte complexes without inducing an overt toxicological response.
authors.affiliation: Centre de Recherche en Biologie de la Reproduction, Département des Sciences Animales, Pavillon Paul-Comtois, Université Laval, Ste-Foy, Québec, Canada.
authors.forename: Céline
authors.initials: C
authors.lastname: Campagna
authors.forename: Pierre
authors.initials: P
authors.lastname: Ayotte
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Sirard
authors.forename: Guylène
authors.initials: G
authors.lastname: Arsenault
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Laforest
authors.forename: Janice L
authors.initials: JL
authors.lastname: Bailey
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004785:Environmental Pollutants / Q000097:blood / Q000633:toxicity*; D005260:Female; D005307:Fertilization in Vitro / Q000187:drug effects*; D006843:Hydrocarbons, Chlorinated / Q000097:blood / Q000633:toxicity*; D007306:Insecticides / Q000378:metabolism / Q000633:toxicity*; D008297:Male; D009865:Oocytes / Q000187:drug effects* / Q000473:pathology / Q000502:physiology; D006080:Ovarian Follicle / Q000187:drug effects* / Q000473:pathology / Q000502:physiology; D013552:Swine
chemical_list: D004338:Drug Combinations; D004785:Environmental Pollutants; D006843:Hydrocarbons, Chlorinated; D007306:Insecticides