Name: NATÁLIA PIMENTEL DA SILVA SOUZA
Publication date: 24/05/2024
Examining board:
Name |
Role |
|---|---|
| LEANDRO MIRANDA ALVES | Examinador Externo |
| ROGER LYRIO DOS SANTOS | Examinador Interno |
Summary: Tributyltin (TBT) is an endocrine-disrupting chemical related to reproductive dysfunctions. Few studies have investigated the effects of TBT exposure on mammary gland development. Therefore, we assessed whether subacute TBT exposure causes irregularities in mammary gland development. We administered TBT (100 or 1000 ng/kg/day for 30 days) to female rats from postnatal day (PND) 25 to PND 55, and mammary gland development, morphology, inflammation, collagen deposition, and protein expression were evaluated. Abnormal mammary gland development was observed in both TBT-exposed rats. Specifically, TBT exposure reduced the number of terminal end buds (TEBs), alveolar buds type 1 (AB1), and type 2 (AB2). An increase in lobule and differentiation (DF) 2 scores was found in the mammary gland of TBT-exposed rats. TBT exposure increased mammary gland blood vessels, mast cell numbers, and collagen deposition. Additionally, both TBT-exposed rats presented intraductal hyperplasia and TEB-like structures. An increase in estrogen receptor alpha (ER), progesterone receptor (PR), and cytochrome P450 family 19 subfamily A member 1 (CYP19A1) protein expression was observed in the mammary gland of TBT-exposed rats. Thus, these data suggest that TBT exposure impairs mammary gland development in female rats.
