Plasma IGF1 and 17β-Estradiol Concentrations During the Follicular Wave in Llamas

ZAMPINI, ENZO; MIRAGAYA, MARCELO; ZAMPINI, ENZO; MIRAGAYA, MARCELO; BIANCHI, CAROLINA; GAMBAROTTA, M.; BIANCHI, CAROLINA; GAMBAROTTA, M.; GALLELLI, MARÍA F.; ABA, MARCELO; GALLELLI, MARÍA F.; ABA, MARCELO

Frontiers in Veterinary Science

Frontiers Media SA

Lugar: Lausana; Año: 2020 vol. 7 p. 1 - 7

The aim of this study was to characterize the temporal association between follicularwaves and circulating concentrations of 17b-estradiol (E2) and IGF1 in llamas. Follicularwaves could be clearly divided in three phases: growth, plateau and regression; with amean duration of 18.8 ± 0.32 days. All follicular waves showed overlapping, so that asone dominant follicle was regressing, another one was growing. E2 plasma concentrationshowed a wavelike pattern, similar to that followed by the dominant follicle; reachingits maximum concentration at the end of the growth phase and decreasing at the endof the plateau phase. IGF1 also showed variations during the follicular wave. It tendedto increase during the growth phase and decreased toward Days 14 and 16. IGF1reached its maximum concentration before E2 did (5 ± 0.8 vs. 7.2 ± 0.5 days afterwave emergence) and before the maximum follicular diameter was attained (10.2 ± 0.46days after wave emergence). Both hormones started to rise again in coincidence with thedevelopment of a new follicular wave. The observed profiles allow to suggest that IGF1could have a role on folliculogenesis and ovarian steroideogenesis in llamas, as reportedfor other species.