Subclinical endometritis increases oxidative stress and modulates polymorphonuclear leukocyte functions in crossbred cows

Subclinical endometritis (SCE) adversely affects fertility and is a diagnostic challenge in bovine practice. In the present study, it was hypothesized that SCE in cows influence the plasma levels of nitric oxide (NO), lipid peroxide (LPO) and polymorphonuclear (PMN) cell functions. Cows with SCE (n,12) were selected on the basis of positive colour reaction of cervico-vaginal mucus (CVM) to Whiteside test, alkaline pH of CVM and presence of > 5% PMN cells in uterine cytology smears. Cows without endometritis served as negative control (n,12). Functions of PMN cells were assessed by estimating superoxide (O 2 ¯) and hydrogen peroxide (H 2 O 2 ) production ability. Further, to assess the inflammatory status and oxidative stress, plasma levels of NO and LPO were measured. The results revealed that cows with SCE had significantly higher H 2 O 2 (19.70±6.43 vs 2.52±0.71 nmol/2 × 106 cells/30 min incubation) in isolated blood PMN cells as compared to non endometritic cows (P<0.05). Similarly, an increased plasma concentrations of NO (81.34±1.70 vs 57.50±1.36 μmol/L) and LPO (712.00±50.39 vs 402.78±21.61 nmol MDA/L) were observed in cows with SCE. The results suggested that SCE increases oxidative stress and PMN cell functions despite being a local inflammation and may have potential in the diagnosis of SCE or monitoring the efficacy of treatment.