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

BARAVALLE ME; ORTEGA HH; STASSI AF; SALVETTI NR; BELOTTI EM; REY F

Mar del Plata

Congreso; Reunión anual de SAIC, SAI, SAFE; 2016

The ovulatory process shares many similarities with an acute inflammatory reactionand cytokines may be implicated in the control of several ovarian functions. Cystic ovarian disease (COD) is an important cause of reproductive failure incattle and the study of the processes that lead to ovulatory failure and persistence of the dominant follicle is the key to understanding the pathogenesis of COD. The aim of this study was to examine the 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) and IL-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 concentrations of progesterone, obtaining dominant follicles around ovulation (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 time of ovulation. Controls were ovariectomized in proestrus (n = 5; C). The expression of IL-8, IL-1β, IL-1 RI, IL-1 RII, IL-1 Ra and IL-4 was evaluated by immunohistochemistry in follicular structures. The IL-8 and IL-1β showed increased expression in granulosa and theca of persistent follicles from P0 group regarding to antral follicles from the control group (as reference structure). IL-1 RI showed lower expression in the granulosa ofantral follicle of P0 relative to P5, P10 and P15 groups. Immunoexpression of IL-1 RII was lower in the granulosa of antral follicles from the control group regarding persistent follicles of all groups, except in P0. The IL-1 Ra and IL-4 showed increased expression in theca of persistent follicle from P0 and P15 groups than antral follicles from the control group. This, suggest that in follicular persistence exist an alteration in inflammatory mechanisms associated with ovulation and interleukins could contribute to follicular persistence associated with COD.