title: Carryover Effects of Acute DEHP Exposure on Ovarian Function and Oocyte Developmental Competence in Lactating Cows.
abstract: We examined acute exposure of Holstein cows to di(2-ethylhexyl) phthalate (DEHP) and its carryover effects on ovarian function and oocyte developmental competence. Synchronized cows were tube-fed with water or 100 mg/kg DEHP per day for 3 days. Blood, urine and milk samples were collected before, during and after DEHP exposure to examine its clearance pattern. Ovarian follicular dynamics was monitored through an entire estrous cycle by ultrasonographic scanning. Follicular fluids were aspirated from the preovulatory follicles on days 0 and 29 of the experiment and analyzed for phthalate metabolites and estradiol concentration. The aspirated follicular fluid was used as maturation medium for in-vitro embryo production. Findings revealed that DEHP impairs the pattern of follicular development, with a prominent effect on dominant follicles. The diameter and growth rate of the first- and second-wave dominant follicles were lower (P < 0.05) in the DEHP-treated group. Estradiol concentration in the follicular fluid was lower in the DEHP-treated group than in controls, and associated with a higher number of follicular pathologies (follicle diameter >25 mm). The pattern of growth and regression of the corpus luteum differed between groups, with a lower volume in the DEHP-treated group (P < 0.05). The follicular fluid aspirated from the DEHP-treated group, but not the controls, contained 23 nM mono(2-ethylhexyl) phthalate. Culturing of cumulus oocyte complexes in the follicular fluid aspirated from DEHP-treated cows reduced the proportion of oocytes progressing to the MII stage, and the proportions of 2- to 4-cell-stage embryos (P < 0.04) and 7-day blastocysts (P < 0.06). The results describe the risk associated with acute exposure to DEHP and its deleterious carryover effects on ovarian function, nuclear maturation and oocyte developmental competence.
authors.affiliation: Department of Animal Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University, Rehovot, 76100, Israel; Center of Excellence in Agriculture and Environmental Health, Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University, Rehovot, 76100, Israel.
authors.forename: Dorit
authors.initials: D
authors.lastname: Kalo
authors.affiliation: Department of Animal Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University, Rehovot, 76100, Israel.
authors.forename: Ron
authors.initials: R
authors.lastname: Hadas
authors.affiliation: Department of Animal Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University, Rehovot, 76100, Israel.
authors.forename: Ori
authors.initials: O
authors.lastname: Furman
authors.affiliation: Interdepartmental Equipment Facility, Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University, Rehovot, 76100, Israel.
authors.forename: Julius
authors.initials: J
authors.lastname: Ben-Ari
authors.affiliation: Center of Excellence in Agriculture and Environmental Health, Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University, Rehovot, 76100, Israel.
authors.forename: Yehoshua
authors.initials: Y
authors.lastname: Maor
authors.affiliation: AXYS Analytical Services Inc., Sidney, British Columbia, V8L 5X2, Canada.
authors.forename: Donald G
authors.initials: DG
authors.lastname: Patterson
authors.affiliation: AXYS Analytical Services Inc., Sidney, British Columbia, V8L 5X2, Canada.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Tomey
authors.affiliation: Department of Animal Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University, Rehovot, 76100, Israel; Center of Excellence in Agriculture and Environmental Health, Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University, Rehovot, 76100, Israel.
authors.forename: Zvi
authors.initials: Z
authors.lastname: Roth
mesh_terms: D000818:Animals; D002417:Cattle; D002467:Cell Nucleus / Q000378:metabolism; D003338:Corpus Luteum / Q000187:drug effects / Q000378:metabolism; D054885:Cumulus Cells / Q000166:cytology / Q000187:drug effects; D003593:Cytoplasm / Q000378:metabolism; D004051:Diethylhexyl Phthalate / Q000097:blood / Q000737:chemistry* / Q000652:urine; D004958:Estradiol / Q000378:metabolism; D030762:Estrous Cycle; D005260:Female; D015571:Follicular Fluid; D007774:Lactation; D008540:Meiosis; D008892:Milk / Q000737:chemistry; D009865:Oocytes / Q000166:cytology* / Q000187:drug effects; D006080:Ovarian Follicle / Q000000981:diagnostic imaging / Q000187:drug effects*; D010053:Ovary / Q000187:drug effects*; D010795:Phthalic Acids / Q000737:chemistry; D012044:Regression Analysis; D053719:Tandem Mass Spectrometry; D014463:Ultrasonography
chemical_list: D010795:Phthalic Acids; D004958:Estradiol; C032279:phthalic acid; D004051:Diethylhexyl Phthalate