Stress during preovulatory period alters pattern expression of adhesion molecules Involved in lymphocyte infiltration in dairy cattle

ETCHEVERS L; RENNA MS; BELOTTI EM; DIAZ PU; REY F; ORTEGA HH; SALVETTI NR; AMWEG AN

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

Proper expression pattern of adhesion molecules must take place both in the circulating leukocytes and in the activated endothelium for leukocyte infiltration into the ovary. These infiltrated leukocytes act by secreting regulatory molecules necessary for ovulation. The aim of this study was to analyze the effect of stress during the preovulatory period on the expression of adhesion molecules in circulating T- and B-cells and in the endothelium of vessels of the medulla and the dominant follicle. Holstein cows with regular estrous cycles without reproductive disease were included. For stress induction, animals (AG; N=7) were challenged with 100 IU of adrenocorticotropin every 12 hours for 4 days before ovulation when ovariectomy was performed (day 18). Control group (CG; N=5) received saline solution in the same schedule. Blood samples were taken on days 15 and 18 for leukocyte isolation. Expression of CD62-L, CD11b and CD44 was evaluated by flow cytometry in T- and B-cells and ovarian expression of VCAM-1 and PECAM-1 was analyzed by immunohistochemistry. A Generalized Linear Model was used to analyze the results. In T-cells, expression of CD44 and CD62-L was lower in the AG (p<0.05) than in the CG. Also, the expression of CD44 and CD11b decreased over time (p<0.05). The percentage of T-cells expressing CD44 and CD62-L decreased in the AG (p<0.05) and over time (p<0.05). In B-cells, CD11b expression was lower in AG than in the CG (p<0.05). Also, the percentage of B-cells expressing CD11b was lower in the AG than in the CG (p<0.05) and the percentage of B-cells expressing CD44 decreased over time (p<0.05). In the dominant follicle endothelium, VCAM-1 expression was lower in the AG than in the CG (p<0.05) while PECAM-1 expression was similar (p>0.05). Our results present novel insights into the effect of stress during the preovulatory period on the expression of adhesion molecules necessary for proper leukocyte migration into the ovary for successful ovulation.