Role of Components of the Insulin-like Growth Factor System in the Early Stages of Ovarian Follicular Persistence in Cattle.

STASSI AF; SALVETTI NR; RODRÍGUEZ FM; REY F; HUBER E; HEIN G; ORTEGA HH; AMWEG AN; GAREIS NC

JOURNAL OF COMPARATIVE PATHOLOGY

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2017

0021-9975

Cystic ovarian disease (COD) is one of the main causes of infertility in dairy cattle. It has beenpostulated that the insulin-like growth factor (IGF) system may contribute to follicularpersistence and development of COD. The initiation of the IGF response is a result of interactionsbetween IGF-binding proteins (IGFBPs) and IGFBP proteases, mainly pregnancy-associatedplasma protein A (PAPP-A). IGFBPs bind IGFs with high affinity and consequently regulatetheir access to IGF receptors (IGFRs). The aim of this research was to determine variations incomponents of the IGF system in the ovaries of cows with persistent follicles induced by longterm administration of progesterone. Proteins of the IGF system were evaluated at 0 (expectedday of ovulation), 5, 10 and 15 days of follicular persistence to determine whether the changesoccur early in the development of COD. The concentrations of IGF1 and IGFBP4 in follicularfluid were similar in all groups with follicular persistence and in control antral follicles. IGFR1and IGFBP4 expression in situ were higher in granulose cells in persistent follicles than incontrol follicles. No differences were found in PAPP-A concentration within follicular fluid inpersistent follicles relative to control antral follicles. These data support the hypothesis that theIGF system is altered in the initial stages of development of follicular persistence and has adeterminant role in ovarian function in cattle.