Exposure to a glyphosate-based herbicide alters the expression of key regulators of mammary gland development on pre-pubertal male rat

ALTAMIRANO, GABRIELA A.; GOMEZ, AYELEN L.; KASS, LAURA; MUÑOZ-DE-TORO, MÓNICA

Buenos Aires

Congreso; Meeting of Latin America Society of Development Biology; 2019

Latin American Society for Developmental Biology

The male rat mammary gland (MG) is a useful model to study the effects of potential endocrine disruptors. We previously reported that perinatal exposure to a glyphosate-based herbicide (GBH) reduced the area and perimeter of male offspring MG on postnatal day 60 (PND60). Here, we evaluated whether the same exposure induce earlier alterations in MG histology and expression of key regulators of its development, which could explain the changes observed on PND60. Pregnant rats were exposed orally through the diet to vehicle (saline solution) or 3.5 mg/kg/day of GBH from gestational day 9 until weaning; on PND21, the male offspring were sacrificed and MG samples were collected. The histology and proliferation of the MG was evaluated and the mRNA expression of estrogen (ESR1) and androgen (AR) receptors, cyclin D1 (Ccnd1), amphiregulin (Areg), insulin-like growth factor 1 (IGF1), epidermal growth factor receptor (EGFR) and IGF1 receptor (IGF1R) was assessed. No differences were observed in mammary epithelial structures between experimental groups; however, proliferation was reduced in GBH3.5 males. Although mRNA expression of AR was not altered, ESR1 and Ccnd1 diminished in the exposed group. Besides, mRNA levels of Areg, IGF1, EGFR and IGF1R were lower in GBH3.5-exposed males. In conclusion, exposure to GBH alters prepubertal male rat MG development. Present results could explain the modifications observed in the MG area and perimeter on PND60.