title: [Proliferation, apoptosis and mammary gland histomorphometry of thyroxine-treated rats on lactation and after weaning and development of offspring].
abstract: The purpose of this study was to evaluate mammary gland histomorphometry and proliferation rate and apoptosis of thyroxine-treated rats by CDC-47 and caspase-3 immunoexpression. The development of thyroxine-treated rats offspring was also evaluated. Thirty-six female rats were used, distributed in two groups, treated and non-treated with thyroxine. After 60 days of treatment, with thyroxine, rats were mated. Six animals/group were sacrificed on the 2nd and 21st days of lactation and on the 5th day after weaning. A significant difference was observed between groups only on the 5th day after weaning. Thyroxine treatment increased apoptosis rate, which was characterized by a higher caspase-3 expression in mammary epithelial cells. Thyroxine-treated mothers presented changed behavior, but there was no significant difference regarding taking care of offspring, as for cleaning offspring and keeping them warm. Taking into account sex and size of offspring, those from control and thyroxine-treated mothers presented no significant difference of weight and weaning. In conclusion, administering low doses of thyroxine increases apoptosis rate, which is characterized by the increased caspase-3 immunoexpression in mammary epithelial cells 5 days after weaning. But does not affect proliferation rate and development of thyroxine-treated rats offspring.
authors.affiliation: Laboratório de Patologia Comparada, Departamento de Patologia Geral, Instituto de Ciências Biológicas, UFMG, Belo Horizonte, MG.
authors.forename: Eveline Dias
authors.initials: ED
authors.lastname: Leite
authors.forename: Edmilson Santos de
authors.initials: ES
authors.lastname: Freitas
authors.forename: Cíntia de Almeida
authors.initials: Cde A
authors.lastname: Souza
authors.forename: Natalia de Melo
authors.initials: Nde M
authors.lastname: Ocarino
authors.forename: Geovanni Dantas
authors.initials: GD
authors.lastname: Cassali
authors.forename: Enio
authors.initials: E
authors.lastname: Ferreira
authors.forename: Mardelene Geisa
authors.initials: MG
authors.lastname: Gomes
authors.forename: Rogéria
authors.initials: R
authors.lastname: Serakides
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001942:Breast Feeding; D016022:Case-Control Studies; D053148:Caspase 3 / Q000187:drug effects / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000187:drug effects / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D004195:Disease Models, Animal; D005260:Female; D007774:Lactation / Q000187:drug effects*; D008297:Male; D008321:Mammary Glands, Animal / Q000187:drug effects* / Q000473:pathology; D008425:Maternal Behavior / Q000187:drug effects / Q000523:psychology; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D013974:Thyroxine / Q000008:administration & dosage / Q000494:pharmacology*; D014886:Weaning
chemical_list: D018797:Cell Cycle Proteins; D053148:Caspase 3; D013974:Thyroxine