Altered expression of estrogen receptors Α and β in bovine ovarian follicular persistence

NOTARO US, HUBER E, RECCE S, STASSI AF, SALVETTI NR, REY F, ORTEGA HH, RODRÍGUEZ FM.

Buenos Aires

Congreso; REUNIÓN CONJUNTA DE SOCIEDADES DE BIOCIENCIAS; 2017

SAIC

Steroid hormone receptors are members of the superfamily of ligand-regulated transcription factors that modulate gene transcriptionby different mechanisms and as a consequence they are ableto activate or repress gene expression. In mammals, estrogensmodulate the growth, differentiation and the female physiologythrough estrogen receptor (ER) α and ERβ. Cystic ovarian diseasecontributes to reproductive deficiency in lactating dairy cows. Theendocrine profile, growth dynamics and histological characteristicsof cystic follicles are similar to those of induced-persistent folliclesin a model of subluteal progesterone administration. The purpose ofthe present study was to analyze the expression of ERα and ERβ byimmunohistochemistry (IHC) in ovarian follicular structures duringthe development of follicular persistence induced in cows by longtime progesterone administration. A low dose of progesterone wasadministered (n=5) for 0 (ovulation time, P0) and 5 (P5), 10 (P10),and 15 (P15) days after the expected day of ovulation using an intravaginalprogesterone-releasing device. Control cows (group C) receivedno additional hormonal treatment. After IHC technique, digitalimage analysis was performed on ovary slides to quantify the immunostainingin preovulatory follicles of the control group as referencestructure and persistent follicles of P0, P5, P10 and P15 groups.ERα expression was higher in preovulatory follicles of the controlgroup than in the persistent follicles of the P5, P10 and P15 groups,in both granulosa and theca interna cells (p 0.05).