title: Histological and histomorphometric alterations in thyroid and adrenals of CD rat pups exposed in utero to methyl thiophanate.
abstract: Pregnant CD rats were treated with an initial dose of 0, 310 or 560 mg/kg bw per day of the fungicide methyl thiophanate (MT) on gestational days 10-14, corresponding to formation of thyroid and adrenal primordia; newborns were sacrificed on postnatal days (PNDs) 10 and 23. No apparent maternal toxicity and no effects on litter size, viability or weight gain were present. Delayed ear pinna detachment and eye opening were present at top dose level. Thyroid histology showed increased irregular nuclei and/or mitoses (PND 10-both doses), cells with necrotic or hydropic changes (PND 23-top dose). The adrenal cortex showed increased karyomegaly and hydropic degeneration (PND 23-both doses). Thyroid histomorphometry showed reduced follicular density, moderately increased follicular cell height and number of nuclei/follicle (PND 10-top dose and PND 23-both doses), suggesting retarded follicular maturation. The adrenal cortex relative area was slightly decreased (PND 10-top dose and PND 23-both doses).MT may act as weak endocrine disrupter, suggesting that attention should be paid to delayed endocrine alterations elicited by agrochemicals.
authors.affiliation: Laboratory of Comparative Toxicology and Ecotoxicology, Istituto Superiore di Sanità, Viale Regina Elena, 299-00161 Rome, Italy. maramghi@iss.it
authors.forename: Francesca
authors.initials: F
authors.lastname: Maranghi
authors.forename: Caterina
authors.initials: C
authors.lastname: Macrí
authors.forename: Claudio
authors.initials: C
authors.lastname: Ricciardi
authors.forename: Anna Velia
authors.initials: AV
authors.lastname: Stazi
authors.forename: Michele
authors.initials: M
authors.lastname: Rescia
authors.forename: Alberto
authors.initials: A
authors.lastname: Mantovani
mesh_terms: D000311:Adrenal Glands / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D000818:Animals; D000831:Animals, Newborn; D004305:Dose-Response Relationship, Drug; D005314:Embryonic and Fetal Development / Q000187:drug effects; D005260:Female; D005333:Fetus / Q000187:drug effects; D005659:Fungicides, Industrial / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D011919:Rats, Inbred Strains; D013875:Thiophanate / Q000633:toxicity*; D013961:Thyroid Gland / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D013997:Time Factors
chemical_list: D005659:Fungicides, Industrial; D013875:Thiophanate