Alteration in some pro and anti-inflammatory cytokines associated with complete and incomplete gestation cycle of cows

The maternal immune response during pregnancy is regulated by a complex array of pro and anti-inflammatory cytokines which provide optimum conditions for the embryo implantation and survival. The possible role of pro and anti-inflammatory cytokines during the complete gestation cycle of ruminants and the difference in their circadian rhythmicity between successful and unsuccessful pregnancies is still unknown. To study this, blood samples were collected from three groups of cows, pregnant (P), non-pregnant (NP) and aborted (ABORT) cows starting from the day of Artificial Insemination (AI) till calving in P cows and till stages of non pregnancy in other cows. Various pro and anti-inflammatory cytokines were estimated by bovine-specific ELISA test and compared. Successful pregnancies had lower levels of pro-inflammatory cytokines (IL-2, IL-6 and IL-8) but higher anti-inflammatory cytokine (IL-10) mainly during implantation. Significant (p < 0.05) increase in pro-inflammatory cytokines and low IL-10 levels was noticed at abortion and at calving. This study indicates that temporal and spatial aspects of reducing the release of various pro-inflammatory cytokines and maintaining high anti-inflammatory cytokines during pregnancy are essentially required for maintenance of pregnancy. Any disturbance in the cytokine equilibrium may lead to persistent inflammation and pregnancy failure.