PSV-B-16 - Correlation Between Plasma, Uterine, and Vaginal Cytokine Concentrations in Postpartum Beef Cows Prior to Artificial Insemination

Abstract: Cytokines have a vital role in reproductive immune environment during the postpartum period. Previous data evaluated uterine and vaginal cytokine concentrations prior to insemination; however, was unable to correlate these data with plasma cytokine concentrations. The objective of this study was to determine relationships between uterine, vaginal, and plasma pro- and anti-inflammatory cytokine concentrations in postpartum beef cows prior to timed artificial insemination (TAI). Bos indicus-influenced beef cows (n=20) free of any physical, health or reproductive-related issues were subjected to the Bee Synch II protocol 8 days prior (d-8) to TAI (d0). Uterine and vaginal flushes and blood were collected on d-3 and d-1. Pregnancy was determined by transrectal ultrasonography on d28 (Pregnant, n=7; Open, n=13). Using the RayBiotech Quantibody Bovine Cytokine Array 1 the following cytokines concentrations were determined: interferon (IFN)-α, IFN-γ, interleukin (IL)-13, IL-1α, IL-1-F5, IL-21, tumor necrosis factor (TNF)-α, chemokine ligand (CXCL)-9, CXCL-10, and chemokine ligand 4 (CCL4). Concentration data were analyzed using PROC GLM and correlations using Pearson correlation in SAS. For plasma samples, 8 pro-inflammatory cytokines (IFN-α, IFN-γ, IL-13, IL-1α, IL-1-F5, IL-21, CXCL-9, and TNF-α) had greater (P< 0.05) concentrations in open cows compared with pregnant cows. For uterine flushes, 3 pro-inflammatory cytokines (IFN-γ, IL-1α, and IL-21) had greater (P< 0.05) concentrations in open cows compared with pregnant cows. For vaginal flushes, IFN-α concentrations were greater (P< 0.05) in open cows, while CXCL-10 concentrations were greater in pregnant cows. There were no significant correlations between plasma and uterine or vaginal samples (P>0.05). Interestingly, for open cows there were correlations for IFN-α (r=0.46; P=0.02), IFN-γ (r=0.58; P=0.002), and IL-21 (r=0.54; P=0.004) between uterine and vaginal samples; however, no correlations were observed for pregnant cows. These results suggest a greater abundance of pro-inflammatory cytokines within the uterus, vagina, and in peripheral circulation for resulting open cows prior to TAI.