title: Effects of dioxin, an environmental pollutant, on mouse blastocyst development and apoptosis.
abstract: OBJECTIVE
  To evaluate the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; dioxin) on mouse embryo development and apoptosis.
  
  
  METHODS
  Controlled animal study.
  
  
  METHODS
  Academic research environment.
  
  
  METHODS
  Female mice (CB6F1) at 3 to 6 weeks of age and proven breeders (C578B46).
  
  
  METHODS
  Mouse embryos were obtained at the morula stage and cultured to the blastocyst stage in a pharmacologic dose of TCDD (3.1 microM) or a control medium. The morphology was assessed, and staining for apoptosis was performed. Immunohistochemistry for the presence of aromatic hydrocarbon receptor (AhR) was performed in another set of morula-stage embryos.
  
  
  METHODS
  The number of embryos developing from the morula to the blastocyst stage and number of apoptotic blastomeres in control vs. TCDD culture conditions.
  
  
  RESULTS
  No statistically significant differences were observed in the percentage of embryos reaching the blastocyst stage: 80.9% (115 of 142) in the TCDD-treated group, vs. 82.9% (121 of 146) in the control group. There was also no difference in the degree of apoptosis: 22.6 +/- 7.3% apoptotic cells (TCDD) vs. 25.3 +/- 9.7% (controls). Staining indicated the slight presence of aromatic hydrocarbon receptor in the morula-stage mouse embryos.
  
  
  CONCLUSIONS
  TCDD at 3.1 microM did not alter the development of early mouse morula to blastocysts and did not significantly induce apoptosis in vitro.
authors.affiliation: Division of Reproductive Endocrinology, Rush Presbyterian St. Luke's Medical Center, Chicago, Illinois, USA. mmatthews@carolinas.org
authors.forename: M
authors.initials: M
authors.lastname: Matthews
authors.forename: I
authors.initials: I
authors.lastname: Heimler
authors.forename: M
authors.initials: M
authors.lastname: Fahy
authors.forename: E
authors.initials: E
authors.lastname: Radwanska
authors.forename: R
authors.initials: R
authors.lastname: Hutz
authors.forename: A
authors.initials: A
authors.lastname: Trewin
authors.forename: R
authors.initials: R
authors.lastname: Rawlins
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001755:Blastocyst / Q000187:drug effects* / Q000502:physiology*; D001757:Blastomeres / Q000187:drug effects / Q000502:physiology; D046508:Culture Techniques; D047108:Embryonic Development; D005314:Embryonic and Fetal Development / Q000187:drug effects; D004785:Environmental Pollutants / Q000494:pharmacology*; D005260:Female; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009028:Morula / Q000187:drug effects / Q000502:physiology; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D011247:Pregnancy; D012016:Reference Values
chemical_list: D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins