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 G; MUÑOZ-DE-TORO M; LUQUE EH

Congreso; REUNION DE SOCIEDADES DE BIOCIENCIAS 2021; 2021

Glyphosate-based herbicides (GBH) are the most widely used agrochemicals raising concern about its effects on animal and human health. We have previously reported that neonatal exposure of ewe lambs to a low dose of GBH induced permanent changes in the uterus and ovaries. Moreover, neonatal exposure of female rats to GBH decreased the fertility rate. Here, our aim was to assess the long-term effects of neonatal oral exposure to GBH in the oviduct of ewe lambs. To achieve this, ewe lambs were orally exposed from postnatal day (PND) 1 to PND14 to vehicle (n=6) or the reference dose of a GBH (1 mg glyphosate/Kg/day) (n=4). Since oviduct is target of estrogen, we also tested the effect of a gonadotrophic stimulus (pFSH, Follitropin 50 mg/day from PND41 to PND43) in GBH treated ewe lambs: vehicle+pFSH (n=6) and GBH+pFSH (n=4). At PND45, the isthmus and ampulla of oviducts were collected, paraffin embedded or stored at -80°C until mRNA extraction. The thickness of the myosalpinx was determined by digital analysis of picrosirius-hematoxylin-stained oviduct in transversal sections using FIJI software. The expression of Ki67 (as cell proliferation marker), and of α-alpha smooth muscle actin (α-SMA) were evaluated by immunohistochemistry. The gene expression of steroid receptors (ERα and 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 of α-SMA or steroid receptors mRNA was found. These results demonstrate that neonatal exposure to a low dose of GBH alone or with a gonadotrophic treatment does not alter the development of the oviduct myosalpinx, which allows us to assume that function of oviduct (gametes transport and fertilization of the oocyte) might not be affected following GBH exposure. Nevertheless, more studies are needed to conclude that the decrease in female fertility due to GBH treatment is not due to oviduct alterations.