Neonatal exposure to a glyphosate-based herbicide and its effects on the oviduct of ewe lambs.

LOVERA L; ALARCÓN R; INGARAMO PI; ALEGRE AL; RIVERA OE; DIOGUARDI GH; MUÑOZ-DE-TORO M; LUQUE EH

modalidad virtual

Otro; Reunión Conjunta de Sociedades de Biociencias 2021: SAIC, SAI, AAFE, NANOMED-ar.; 2021

Glyphosate-based herbicides (GBH) are the most widely used agrochemicals raising concern about its effects on animal and humanhealth. We have previously reported that neonatal exposure of ewelambs to a low dose of GBH induced permanent changes in theuterus and ovaries. Moreover, neonatal exposure of female rats toGBH decreased the fertility rate. Here, our aim was to assess thelong-term effects of neonatal oral exposure to GBH in the oviductof ewe lambs. To achieve this, ewe lambs were orally exposed frompostnatal day (PND) 1 to PND14 to vehicle (n=6) or the referencedose of a GBH (1 mg glyphosate/Kg/day) (n=4). Since oviduct istarget of estrogen, we also tested the effect of a gonadotrophic stimulus (pFSH, Follitropin 50 mg/day from PND41 to PND43) in GBHtreated ewe lambs: vehicle+pFSH (n=6) and GBH+pFSH (n=4). AtPND45, the isthmus and ampulla of oviducts were collected, paraffinembedded or stored at -80°C until mRNA extraction. The thicknessof the myosalpinx was determined by digital analysis of picrosirius-hematoxylin-stained oviduct in transversal sections using FIJIsoftware. The expression of Ki67 (as cell proliferation marker), andof α-alpha smooth muscle actin (α-SMA) were evaluated by immunohistochemistry. The gene expression of steroid receptors (ERαand PR) was evaluated by RT-PCR. The thickness of the myosalpinx and cell proliferation showed no differences between the experimental groups. Moreover, no alterations in the expression ofα-SMA or steroid receptors mRNA was found. These results demonstrate that neonatal exposure to a low dose of GBH alone or witha gonadotrophic treatment does not alter the development of theoviduct myosalpinx, which allows us to assume that function of oviduct (gametes transport and fertilization of the oocyte) might not beaffected following GBH exposure. Nevertheless, more studies areneeded to conclude that the decrease in female fertility due to GBHtreatment is not due to oviduct alterations.