title: Cellular proliferation rate and insulin-like growth factor binding protein (IGFBP)-2 and IGFBP-3 and estradiol receptor alpha expression in the mammary gland of dairy heifers naturally infected with gastrointestinal nematodes during development.
abstract: Mammary ductal morphogenesis during prepuberty occurs mainly in response to insulin-like growth factor-1 (IGF-1) and estradiol stimulation. Dairy heifers infected with gastrointestinal nematodes have reduced IGF-1 levels, accompanied by reduced growth rate, delayed puberty onset, and lower parenchyma-stroma relationship in their mammary glands. Immunohistochemical studies were undertaken to determine variations in cell division rate, IGF-1 system components, and estradiol receptors (ESR) during peripubertal development in the mammary glands of antiparasitic-treated and untreated Holstein heifers naturally infected with gastrointestinal nematodes. Mammary biopsies were taken at 20, 30, 40, and 70 wk of age. Proliferating cell nuclear antigen immunolabeling, evident in nuclei, tended to be higher in the parenchyma of the glands from treated heifers than in those from untreated. Insulin-like growth factor binding proteins (IGFBP) type 2 and type 3 immunolabeling was cytoplasmic and was evident in stroma and parenchyma. The IGFBP2-labeled area was lower in treated than in untreated heifers. In the treated group, a maximal expression of this protein was seen at 40 wk of age, whereas in the untreated group the labeling remained constant. No differences were observed for IGFBP3 between treatment groups or during development. Immunolabeling for α ESR (ESR1) was evident in parenchymal nuclei and was higher in treated than in untreated heifers. In the treated group, ESR1 peaked at 30 wk of age and then decreased. These results demonstrate that the parasite burden in young heifers negatively influence mammary gland development, affecting cell division rate and parameters related to estradiol and IGF-1 signaling in the gland.
authors.affiliation: Laboratorio de Regulación Hipofisaria, Instituto de Biología y Medicina Experimental, Vuelta de Obligado 2490, 1428, Ciudad Autónoma de Buenos Aires, Argentina; Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, 3080, Esperanza, Santa Fe, Argentina.
authors.forename: A F
authors.initials: AF
authors.lastname: Perri
authors.affiliation: Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, 3080, Esperanza, Santa Fe, Argentina.
authors.forename: B E
authors.initials: BE
authors.lastname: Dallard
authors.affiliation: Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, 3080, Esperanza, Santa Fe, Argentina.
authors.forename: C
authors.initials: C
authors.lastname: Baravalle
authors.affiliation: Laboratorio de Regulación Hipofisaria, Instituto de Biología y Medicina Experimental, Vuelta de Obligado 2490, 1428, Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: N
authors.initials: N
authors.lastname: Licoff
authors.affiliation: Esc. Inchausti, Universidad Nacional de La Plata, 6667, 25 de mayo, Pcia. de Buenos Aires, Argentina.
authors.forename: N
authors.initials: N
authors.lastname: Formía
authors.affiliation: Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, 3080, Esperanza, Santa Fe, Argentina.
authors.forename: H H
authors.initials: HH
authors.lastname: Ortega
authors.affiliation: Laboratorio de Regulación Hipofisaria, Instituto de Biología y Medicina Experimental, Vuelta de Obligado 2490, 1428, Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: D
authors.initials: D
authors.lastname: Becú-Villalobos
authors.affiliation: Laboratorio de Regulación Hipofisaria, Instituto de Biología y Medicina Experimental, Vuelta de Obligado 2490, 1428, Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: M E
authors.initials: ME
authors.lastname: Mejia
authors.affiliation: Laboratorio de Regulación Hipofisaria, Instituto de Biología y Medicina Experimental, Vuelta de Obligado 2490, 1428, Ciudad Autónoma de Buenos Aires, Argentina. Electronic address: ilacau@ibyme.conicet.gov.ar.
authors.forename: I M
authors.initials: IM
authors.lastname: Lacau-Mengido
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000494:pharmacology; D002417:Cattle / Q000469:parasitology; D049109:Cell Proliferation; D004958:Estradiol / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005273:Fenbendazole / Q000494:pharmacology; D041981:Gastrointestinal Tract / Q000469:parasitology; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000235:genetics / Q000378:metabolism*; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000235:genetics / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism; D007559:Ivermectin / Q000494:pharmacology; D007978:Levamisole / Q000494:pharmacology; D008321:Mammary Glands, Animal / Q000166:cytology / Q000378:metabolism*; D009348:Nematoda; D009349:Nematode Infections / Q000662:veterinary*; D015398:Signal Transduction
chemical_list: D000871:Anthelmintics; D047628:Estrogen Receptor alpha; D018971:Insulin-Like Growth Factor Binding Protein 2; D018972:Insulin-Like Growth Factor Binding Protein 3; D007978:Levamisole; D004958:Estradiol; D005273:Fenbendazole; D007334:Insulin-Like Growth Factor I; D007559:Ivermectin
keywords: estradiol receptor alpha; insulin-like growth factor binding protein; prepubertal mammary gland; proliferating cell nuclear antigen