Neonatal exposure of ewe lambs to a glyphosate-based herbicide adversel y affects ovarian follicular development independently of administration route.

ENRIQUE H. LUQUE.; RAMIRO ALARCÓN; OSCAR E. RIVERA ,; MÓNICA M. MUÑOZ-DE-TORO ,; NORBERTO M. BELMONTE,; PAOLA I. INGARAMO; GISELA H. DIOGUARDI

Congreso; Reunión Conjunta de Biociencias.; 2017

Glyphosate-based herbicides (GBH) are widely used around theworld. Previous studies suggest that GBH may act as endocrine disruptor. Our hypothesis suggests that low doses of GBH affect ovarian ovine development. Ewe lambs were exposed from postnatal day(PND) 1 to PND14 to sc (n: 13) or orally (n: 5) environmentally relevant doses of GBH (2 mg/Kg/day, EPA reference dose) and controls(n: 13) with saline solution. On PND 45 ovaries were weighted andparaffn-embedded, sectioned in 4 adjacent 5 µm -serial sectionstaken 200 µm apart. Follicular dynamic was established by histomorphological features on picrosirious-hematoxilin-stained sections(8 sections/ovary). Follicles of different types and multioocyte follicles were expressed as a percentage. Immunohistochemistry of androgen receptor (AR) and Ki (proliferation marker) were evaluated.Proliferation was measured in granulose (GC) and theca cells (TC)of antral follicles. GBH treatment did not alter ovarian weight, totalnumber of follicles or AR expression. Lambs exposed to GBH showeda reduction of primordial follicles (C=87.9+2.7; scGBH=57.8+3.9;oGBH=62.7+5.4) together with an increase of transitory (C=6.8+1.7;scGBH=36.2+3.3; oGBH=30.7+4.6) and primary (C=1.4+0.2; scGBH=4.4+0.9; oGBH=5.2+1) follicles. In addition, GBH treatmentincreased the percentage of atretic follicles (C=29.0+3.7; scGBH=44.3+4.0; oGBH=44.3+2.9) and induced higher proliferationof GC (C=26.3+5.5; scGBH=43.3+5.1; oGBH=52.8+11.1) andTC (C=4.9+0.9; scGBH=11.1+1.6; oGBH=28.7+4.8) in antral follicles. Moreover, an increased incidence of multioocyte follicles(C=0.1+0.1; scGBH=1.3+0.4; oGBH=1.1+0.3) was observed. Ourresults demonstrated that neonatal exposure to low doses of GBHdisrupts the ovine follicular development independently of administration route, showing no differences between sc and oral treatment.Further studies with the same GBH protocol will defne whether thedescribed effects have consequences in the adult ovarian function.