[Proliferation, apoptosis and mammary gland histomorphometry of thyroxine-treated rats on lactation and after weaning and development of offspring].
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.
Leite
Eveline Dias
ED
Laboratório de Patologia Comparada, Departamento de Patologia Geral, Instituto de Ciências Biológicas, UFMG, Belo Horizonte, MG.
Freitas
Edmilson Santos de
ES
Souza
Cíntia de Almeida
Cde A
Ocarino
Natalia de Melo
Nde M
Cassali
Geovanni Dantas
GD
Ferreira
Enio
E
Gomes
Mardelene Geisa
MG
Serakides
Rogéria
R
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
D018797:Cell Cycle Proteins; D053148:Caspase 3; D013974:Thyroxine