Modified expression of cytokines in persistent follicles induced by prolonged treatment with progesterone in cows

STASSI A.; BELOTTI, E.M.; BARAVALLE M.E.; SALVETTI NR.; REY, F.; ORTEGA, H.H.

Mar del Plata

Congreso; LXI REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIÓN CLÍNICA (SAIC); 2016

SAIC

The ovulatory process shares many similarities with an acuteinflammatory reaction and cytokines may be implicated in thecontrol of several ovarian functions. Cystic ovarian disease(COD) is an important cause of reproductive failure in cattleand the study of the processes that lead to ovulatory failure andpersistence of the dominant follicle is the key to understandingthe pathogenesis of COD. The aim of this study was to examinethe expression of interleukin IL-8, IL-1β, IL-1 receptor I (IL-1 RI),IL-1 receptor II (IL-1 RII), IL-1 receptor antagonist (IL-1 Ra) andIL-4 in ovaries of animals with induced follicular persistence.An experimental model of follicular persistence was performed,with an intravaginal progesterone device to get subluteal concentrationsof progesterone, obtaining dominant follicles aroundovulation (n = 5; P0) and follicles that persist for 5 (n = 5; P 5),10 (n = 5; P10) or 15 days (n = 5; P15) after the expected timeof ovulation.Controls were ovariectomized in proestrus (n = 5; C). Theexpression of IL-8, IL-1β, IL-1 RI, IL-1 RII, IL-1 Ra and IL-4 wasevaluated by immunohistochemistry in follicular structures. TheIL-8 and IL-1β showed increased expression in granulosa andtheca of persistent follicles from P0 group regarding to antralfollicles from the control group (as reference structure). IL-1 RIshowed lower expression in the granulosa of antral follicle of P0relative to P5, P10 and P15 groups. Immunoexpression of IL-1RII was lower in the granulosa of antral follicles from the controlgroup regarding persistent follicles of all groups, except in P0.The IL-1 Ra and IL-4 showed increased expression in theca ofpersistent follicle from P0 and P15 groups than antral folliclesfrom the control group. This, suggest that in follicular persistenceexist an alteration in inflammatory mechanisms associated withovulation and interleukins could contribute to follicular persistenceassociated with COD.