In vitro cow uterine response to Escherichia coli, leukotrienes and cytokines

The aim was to determine the dynamic profile of interactions between Escherichia coli (E. coli) and the actions of leukotrienes (LTs) and TNF and INFγ (cytokines) in the uterus in vitro. Uterine explants (N=6) were incubated for 2, 12 and 24h either as E. coli-treated (10⁶CFU) or non-treated and/or with: LTB₄ and C₄ (10^-6M, for both LTs), LTs receptors antagonists (aLTR; 10^-6M) and/or cytokines (each 10ng/ml). Toll Like Receptor 4 (TLR4) mRNA expression increased in explants incubated with E. coli, cytokines and LTs after 2 and 12h and aLTR inhibited the effect of LTs in explants incubated with E. coli (P<0.05). IL-6 mRNA expression was up-regulated in E.coli-treated explants with cytokines after 2h and cytokines with LTs after 12h (P<0.05). E. coli increased prostaglandin (PG)E₂ output after all examined time points, and PGF_2α and IL-6 levels in E.coli-treated explants after 12 and 24h with cytokines, with LTs (P<0.05). aLTR inhibited LT stimulating action on PGs and IL-6 output in explants incubated with E. coli after 12 and 24h (P<0.05). LTs modify and enhance experimentally induced infection: TLR4 and IL-6 mRNA expression, IL-6 and PGs secretion, and cytokines participate in this process.