Elastase, Myeloperoxidase, and Alkaline Phosphatase Release and Free Radical Generation in Neutrophils Isolated from Blood of Sows at Different Stages of Oestrous Cycle

The aim of the study was to assess the influence of the oestrous cycle phase on neutrophil secretory activity and to extrapolate it to susceptibility to uterine infections. The obtained results indicate that the highest enzyme release seen in the late follicular phase (elastase release was 42.18 ±3.11% of maximal release, myeloperoxidase was 45.0 ±5.12%, and alkaline phosphatase was 44.75 ±9.0%) was related to the level of 17β-oestradiol in plasma. Similarly, a free radical generation was also the most enhanced during this phase. Significantly lower values were obtained from sows during the luteal phase in regard to both enzyme release (36.62 ±3.58% for elastase, 27.87 ±8.7% for myeloperoxidase, and 22.12 ±2.4% for alkaline phosphatase), and that of free radicals (2.28 1.6 μM/106 cells for nitric oxide and 2.47 0.6 nM/106 cells for superoxide).