title: Peri-conceptional changes in maternal exposure to sewage sludge chemicals disturbs fetal thyroid gland development in sheep.
abstract: Ewes were exposed to sewage sludge-fertilized pastures in a study designed investigate pre-conceptual and/or gestational exposure to environmental chemicals. The in utero impact on fetal thyroid morphology and function at day 110 (of 145) of pregnancy was then determined. Pre-conceptual exposure increased the relative thyroid organ weights in male fetuses. The number of thyroid follicles in thyroids of fetuses after pre-conceptual or gestational exposure was reduced. This correlated with an increase in Ki67 positive cells. Pre-conceptual exposure to sewage sludge reduced small blood vessels in fetal thyroids. Thyroid tissues of exposed fetuses contained regions where mature angio-follicular units were reduced exhibiting decreased immunostaining for sodium-iodide symporter (NIS). Fetal plasma levels of fT3 and fT4 in exposed animals, however, were not different from controls suggesting compensatory changes in the thyroid gland to maintain homeostasis in exposed fetuses. The regional aberrations in thyroid morphology may impact on the post-natal life of the exposed offspring.
authors.affiliation: Department of Human Anatomy & Cell Science, University of Manitoba, Winnipeg, Manitoba, Canada. hombach@cc.umanitoba.ca
authors.forename: Sabine
authors.initials: S
authors.lastname: Hombach-Klonisch
authors.forename: Adrian
authors.initials: A
authors.lastname: Danescu
authors.forename: Farhana
authors.initials: F
authors.lastname: Begum
authors.forename: Maria R
authors.initials: MR
authors.lastname: Amezaga
authors.forename: Stewart M
authors.initials: SM
authors.lastname: Rhind
authors.forename: Richard M
authors.initials: RM
authors.lastname: Sharpe
authors.forename: Neil P
authors.initials: NP
authors.lastname: Evans
authors.forename: Michelle
authors.initials: M
authors.lastname: Bellingham
authors.forename: Corinne
authors.initials: C
authors.lastname: Cotinot
authors.forename: Beatrice
authors.initials: B
authors.lastname: Mandon-Pepin
authors.forename: Paul A
authors.initials: PA
authors.lastname: Fowler
authors.forename: Thomas
authors.initials: T
authors.lastname: Klonisch
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001808:Blood Vessels / Q000187:drug effects / Q000473:pathology; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D047109:Fetal Development / Q000187:drug effects; D005333:Fetus / Q000187:drug effects / Q000473:pathology*; D008297:Male; D018811:Maternal Exposure; D009929:Organ Size / Q000187:drug effects; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012722:Sewage / Q000737:chemistry*; D012756:Sheep / Q000196:embryology*; D027981:Symporters / Q000378:metabolism; D013961:Thyroid Gland / Q000098:blood supply / Q000187:drug effects* / Q000196:embryology* / Q000473:pathology; D013963:Thyroid Hormones / Q000097:blood; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D000099209:Sodium-Iodide Symporters
chemical_list: D012722:Sewage; D027981:Symporters; D013963:Thyroid Hormones; D014874:Water Pollutants, Chemical; D000099209:Sodium-Iodide Symporters