Increased recruitment of granulocytes in the ovaries of dairy cows with cystic ovarian disease (COD).

STASSI AF; ETCHEVERS L; ACOSTA V; VILLALBA L; CAINELLI S; SALVETTI NR; REY F; ORTEGA HH

Mar del Plata, Buenos Aires Argentina.

Congreso; Reunión Conjunta SAIC, SAI, FAIC, SAFIS 2022. LXVII Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC). 16 al 19 de noviembre de 2022.; 2022

SAIC

COD is among the most relevant cause of subfertility in dairy cattle and is the result of ovulation failure. Ovulation has been characterized as an inflammatory process in which granulocytes are involved. Therefore, the aim of this study was to evaluate the distribution of granulocytes (CH138+) in ovaries of animals with spontaneous COD and control (C) animals. Ovariectomy was performed in animals with COD to obtain ovaries (n = 5), also control cows were ovariectomized in proestrus (n = 5). CH138+ cells were evaluated through immunohistochemistry in total ovary (TO), in ovarian cortex (OC), medulla (OM), theca interna (TI) and externa (TE) of cysts and dominant follicles. In addition, CH138+ cells were evaluated by immunocytochemistry performed on samples of follicular fluid from (FF) cysts and dominant follicles. The specificity of the antibody was corroborated by western blot (WB). The data was analyzed using ANOVA with Duncan’s post-test and T-student test. WB analysis detected a strong positive band of 17 KDa for CH138. Comparison between groups showed that, the number of CH138+ cells was higher in TO, OM and TE of COD group than in C group (p<0.05). The analysis within group showed that, CH138+ cells in the C group were lower in TI and TE than OC and OM (p<0.05). CH138+ cellsin the COD group were lower in TI than TE, OC and OM (p<0.05). Finally, CH138+ cells in FF of the COD group were similar to the C group (p>0.05). This is the first description about the evaluation of granulocytes in FF in cattle with COD. Growing evidence indicates that infiltrated leukocytes, such as granulocytes, produce additional cytokines and chemokines, acting as in situ modulators of ovarian function. These results demonstrate that the immune system and inflammatory pathways are strongly involved in ovarian events related to this disease. Therefore, we propose that this high proportion of these cells could be related to the anovulation observed in COD.