Perinatal exposure to glyphosate-based herbicide alters the thyrotrophic axis and causes thyroid hormone homeostasis imbalance in male rats

• DOI: 10.1016/j.tox.2016.11.005
• Publication Date: 2016-12-01T18:16:18Z
• Authors: Janaina Sena de S...; Marina Malta Letr...; Rodrigo Rodrigues...; Gabriel Glebocki; Renata Marino Romano; Tania Maria Ortig...; Gisele Giannocco; Ismael Dale Cotri...; Magnus Regios Dia...; Marco Aurélio Romano; Maria Izabel Chia...
• Keywords: DIO2; Hypothalamic–pituitary–thyroid axis; Thyroid hormone receptor

Glyphosate-based herbicides (GBHs) are widely used in agriculture. Recently, several animal and epidemiological studies have been conducted to understand the effects of these chemicals as an endocrine disruptor for gonadal system. The aim present study was determine whether GBHs could also disrupt hypothalamic-pituitary-thyroid (HPT) axis. Female pregnant Wistar rats were exposed a solution containing GBH Roundup®Transorb (Monsanto). animals divided into three groups (control, 5mg/kg/day or 50mg/kg/day) from gestation day 18 (GD18) post-natal 5 (PND5). Male offspring euthanized at PND 90, blood tissues samples hypothalamus, pituitary, liver heart collected hormonal evaluation (TSH-Thyroid stimulating hormone, T3-triiodothyronine T4-thyroxine), metabolomic mRNA analyses genes related thyroid hormone metabolism function. profiles showed decreased concentrations TSH groups, with no variation levels hormones (THs) T3 T4 between groups. Hypothalamus gene expression analysis revealed reduction encoding deiodinases 2 (Dio2) 3 (Dio3) TH transporters Slco1c1 (former Oatp1c1) Slc16a2 Mct8). In Dio2, receptor (Thra1 Thrb1), higher than control group. Interestingly, Tshb did not show any difference profile Liver Thra1 Thrb1 increased both GBH-exposed heart, Mb, Myh6 Mhca) Slc2a4 Glut4) Additionally, correlation data similar alterations detected hypothyroid rats. Perinatal exposure male modified HPT set point, lower likely reflecting post-translational events. Several regulated by involved transport presented varying degrees alteration that probably programmed during intrauterine reflects peripheral metabolism. conclusion, role axis disruption should be considered populations this herbicide.