Effects of developmental exposure to glyphosate and propiconazole on the male rat mammary gland

GOMEZ AL; ALTAMIRANO GA; SCHIERANO-MAROTTI G; MUÑOZ-DE-TORO M; KASS L

Congreso; Reunión Anual de Sociedades de Biociencias. Sociedad Argentina de Investigación Clínica, Modalidad Virtual.; 2020

Several agrochemicals have been shown to impaired mammary glanddevelopment, some of them acting as endocrine disrupting chemicals.  Since the male rat mammary gland issusceptible to endocrine disruption, it is a useful model to study the effectsof these compounds. Here, we evaluated whether developmentalexposure to glyphosate (GLY), propiconazole (PRO) or both (PROGLY) alter themammary gland morphology and its endocrine response in postpubertal male rats.Pregnant rats were exposed orally to vehicle (saline solution), 4 mg/kg/day ofGLY, 4 mg/kg/day of PRO or both doses of GLY and PRO, from gestation day 9 untilweaning. On postnatal day 60, the male offspring were sacrificed and mammarygland samples were collected. Totalarea, perimeter, longitudinal growth, number of terminal end buds and mammary development score were analyzed inmammary gland whole-mounts (WMs). Lobuloalveolar development and the presence ofhyperplastic structures were evaluated in histological sections, as well as estrogen(ESR1) and androgen receptor (AR) protein expression. Among the parametersevaluated in WM, only mammary gland total area was reduced in GLY exposed males(Control: 492±16 mm2, GLY: 419±21 mm2, PRO: 436±17 mm2,PROGLY: 473±19 mm2; Control vsGLY p<0.05). Regarding mammary gland morphology, PRO animals presented anenhance lobuloalveolar development (p<0.05) and 27% of the animals developedlobular hyperplasias, whereas no differences were observed in the percentage ofhyperplastic ducts between experimental groups (p>0.05). The proteinexpression of ESR1 was lower in GLY males (Control: 15.3±0.72%,GLY: 11.0±0.74%, PRO: 15.5±1.4, PROGLY: 12.6±1.0%; Control vs GLY p<0.05) and AR expression wassimilar between experimental groups (p>0.05). In conclusion, GLY and PROhave different effects in mammary gland development; however, these effects arenot observed when the males are exposed to both compounds.