Morphological characterization and immunolocalization of hormonal receptors and cell proliferation marker in mammary gland of primiparous and multiparous senescent mice during pregnancy and postpartum

• Grant number: 24/20898-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2025
• End date: January 31, 2026
• Field of knowledge: Biological Sciences - Morphology - Histology
• Principal Investigator: Sílvio Roberto Consonni
• Grantee: Fernanda Silva de Oliveira
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The mammary gland is made up of tissue that undergoes major changes throughout an organism's life, being dependent on several endogenous and exogenous factors. The development of this organ is only completed after pregnancy, during lactation, with morphological and hormonal changes in this tissue. These changes may have an influence on the development of breast cancer, providing protection against this disease, especially when associated with factors such as age at first pregnancy and number of births. This phenomenon is observed in both humans and rodents. Thus, the use of these animals as a study model allows for a better understanding and characterization of the changes associated with the occurrence of pregnancy and birth. Thus, the initial proposal of this project is to evaluate, characterize and morphologically compare the mammary gland, regarding the branching of the ducts and the differentiation of the secretory portion, perform the immunolocalization of proliferation markers and hormonal receptors for estrogen, progesterone, prolactin and relaxin in primiparous and multiparous mice during pregnancy and postpartum. Morphological analyzes of the mammary gland will be carried out, using histological techniques of light microscopy and whole-mounting, in addition to evaluating the profile of hormonal receptors for estrogen, progesterone, prolactin and relaxin by immunolocalization, and evaluating cell proliferation using Ki67 . Biological materials will be collected on days 12 (D12) and 18 (D18) of pregnancy, 3 (3dpp) and 21 (21dpp) days postpartum. Thus, the data obtained may contribute to the understanding of the morphogenesis and expression of hormonal receptors in the mammary gland stimulated by pregnancy resulting from the number of pregnancies and age that may corroborate the idea of protection against breast cancer, comparing these mammary glands in animals during the first and sixth pregnancy.