Altered chemotaxis and mononuclear cell infiltration in bovine ovary after acth stimulation

ETCHEVERS L; STASSI AF; BELOTTI EM; CABAÑA E; ANGELI E; DÍAZ PU; REY F; SALVETTI NR; ORTEGA HH; AMWEG AN

Congreso; Reunión Conjunta SAIC SAI AAFE NANOMED; 2021

Before ovulationthe ovary exhibits signs of local inflammation: chemokine and cytokine release,vasodilation, leukocyte infiltration; and altered immune responses in ovaryoften results in reproductive failures. However, the effects of adrenocorticotropin(ACTH) on the complexity of this inflammatory response are not yet well described.The aim of this study was to evaluate the effect of ACTH during preovulatoryperiod on the number of mononuclear cells (MCs) infiltrated in the ovary and onthe mechanisms associated with cell infiltration. ACTH (100 IU) wasadministered to Holstein cows (n=11) during proestrus every 12 h for four days beforeovulation when ovariectomy was performed (day 18). Daily ovarian Dopplerultrasonography was used to evaluate the percentage of irrigated area (IA), thepulsatility and resistance index on the dominant follicles. Also, blood sample wastaken on day 18 to analyze alterations on circulating MCs using an hematologyanalyzer. Macrophages (CD14), T (CD2) and B (CD79) lymphocytes distribution inovary was analyzed by immunohistochemistry. In follicular wall samples, geneexpression of chemokines MCP1, IL8, CXCL1, CCL25 were evaluated. And, IL17aexpression was analyzed by western blot. A Generalized Linear Model was used toanalyze the results. The number of systemic monocytes and lymphocytes weresimilar between groups (p>0.05). However, the total number of CD14, CD79 andCD2 infiltrated cells were lower in ACTH group than in control group (p<0.05).The IA showed to be higher on day 18 than in day 16 and 17 (p<0.05) but noeffects of treatment (T) or interaction (T x time) was found (p>0.05). Chemokine?sgene expression showed a lower mRNA of CCL25 on ACTH group (p<0.05). IL17aprotein expression was similar between groups (p>0.05). Our results suggestthat ACTH, released as consequence of stress in preovulatory period, couldimpair MCs infiltration in bovine ovary and this could be due to a lowerchemotaxis capacity of the ovary.