title: Effects of Mono-(2-Ethylhexyl) Phthalate and Di-(2-Ethylhexyl) Phthalate Administrations on Oocyte Meiotic Maturation, Apoptosis and Gene Quantification in Mouse Model.
abstract: OBJECTIVE
  Phthalates, which are commonly used to render plastics into soft and flexible materials, have also been determined as developmental and reproductive toxicants in human and animals. The purpose of this study was to evaluate the effect of mono-(2- ethylhexyl) phthalate (MEHP) and di-(2-ethylhexyl) phthalate (DEHP) oral administrations on maturation of mouse oocytes, apoptosis and gene transcription levels.
  
  
  METHODS
  In this experimental study, immature oocytes recovered from Naval Medical Research Institute (NMRI) mouse strain (6-8 weeks), were divided into seven different experimental and control groups. Control group oocytes were retrieved from mice that received only normal saline. The experimental groups I, II or III oocytes were retrieved from mice treated with 50, 100 or 200 µl DEHP (2.56 µM) solution, respectively. The experimental groups IV, V or VI oocytes were retrieved from mouse exposed to 50, 100 or 200 µl MEHP (2.56 µM) solution, respectively. Fertilization and embryonic development were carried out in OMM and T6 medium. Apoptosis was assessed by annexin V-FITC/Dead Cell Apoptosis Kit, with PI staining. In addition, the mRNA levels ofPou5f1, Ccna1andAsah1were examined in oocytes. Finally, mouse embryo at early blastocyst stage was stained with acridine-orange (AO) and ethidium-bromide (EB), in order to access their viability.
  
  
  RESULTS
  The proportion of oocytes that progressed up to metaphase II (MII) and 2-cells embryo formation stage was significantly decreased by exposure to MEHP or DEHP, in a dose-dependent manner. Annexin V and PI positive oocytes showed greater quantity in the treated mice than control. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) revealed that expression levels ofPou5f1, Asah1andCcna1were significantly lower in the treated mouse oocytes than control. The total cell count for blastocyst developed from the treated mouse oocytes was lower than the controls.
  
  
  CONCLUSIONS
  These results indicate that oral administration of MEHP and DEHP could negatively affect mouse oocyte meiotic maturation and developmentin vivo, suggesting that phthalates could be risk factors for mammalians' reproductive health. Additionally, phthalate-induced changes inPou5f1, Asah1andCcna1transcription level could explain in part, the reduced developmental ability of mouse-treated oocytes.
authors.affiliation: Department of Anatomical Science, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Cellular and Molecular Research Center, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Forouzan
authors.initials: F
authors.lastname: Absalan
authors.affiliation: Cellular and Molecular Research Center, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Sadegh
authors.initials: S
authors.lastname: Saremy
authors.affiliation: Department of Anatomical Science, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Cellular and Molecular Research Center, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Esrafil
authors.initials: E
authors.lastname: Mansori
authors.affiliation: Department of Anatomical Science, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Cellular and Molecular Research Center, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Mahin
authors.initials: M
authors.lastname: Taheri Moghadam
authors.affiliation: Department of Anatomical Science, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Ali Reza
authors.initials: AR
authors.lastname: Eftekhari Moghadam
authors.affiliation: Department of Molecular Biology and Development, Faculty of Medicine, Kazerun Islamic Azad University, Kazerun, Iran.
authors.forename: Razie
authors.initials: R
authors.lastname: Ghanavati
keywords: Apoptosis; Gene Expression; Oocyte Maturation