Proliferação, apoptose e histomorfometria da glândula mamária de ratas tratadas com tiroxina durante a gestação, lactação e após o desmame e desenvolvimento pós-natal dos filhotes

• Ano de defesa: 2006
• Autor(a) principal: Eveline Dias Leite
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: glandula mamaria; rata; apoptose; gestação; Rato como animal de laboratório; Tiroxina; Apoptose; Glândulas mamárias; Rato Reprodução; Lactação
• Link de acesso: http://hdl.handle.net/1843/LGPD-6NBQK3

In two different experiments it was studied the effect of the usage of thyroxine in the mammary gland of rats Wistar during the pregnancy, lactation and after the removal of the litter. It has also been studied the mother´s behavior and the development of the rats nestling treated with thyroxine during the lactation period.In each experiment were used 36 rats in adult age divided in two groups, treated and control. After 60 days from the beginning of the treatment with thyroxine in the drinking water, the rats were coupled, and the intercourse was confirmed by the presence of spermatozoa in the vaginal smear.In the first experiment, six animals/group were sacrified on the seventh, 14th and 19th day of pregnancy. In the second experiment, six animals/group were sacrified on the second and 21st day of lactation and on the 5th day after the removal of the litter. During the pregnancy, the treatment with thyroxine accelerated the development of the mammary gland significantly, although without alterating the proliferation and apoptosi of the epitelial cells rates. During the lactation, the treatment with thyroxine has not changed the histomorfometric characteristics, the proliferation index and the mammary gland apoptosi rate. However on the fifth day of the gland´s involution, the treatment with thyroxine increased the apoptosi rate. The mothers treated with thyroxine presented behavior changed concerning the offspring´s care, especially about the cleaning and heating of the nestling. Although it has not disabled the nestling to grow. The average weight and the age of the eyes opening of the nestling from the mothers treated with thyroxine, during all the breast-feeding period were similar to those of the nestling from non treated mothers. We conclude that the usage of thyroxine accelerates the development of the mammary gland during the pregnancy because it stimulates the mammary epitelial differentiation and it does not change the mammary gland nor the development of the nestling during the lactation, but it accelerates the involution process of the gland after the wean