Participation of neuropeptide Y and its receptors in leukotriene generation in the pig inflamed endometrium

The aim of the study was to determine neuropeptide Y (NPY) receptor subtypes 1 (Y1R) and 2 (Y2R) mRNA and protein abundances in the inflamed porcine endometrium and NPY influence alone and with Y1R or Y2R antagonists on 5-lipoxygenase (5-LOX), LTA4 hydrolase (LTAH) and LTC4 synthase (LTCS) protein abundances and LTB4 and LTC4 release from this tissue. Either saline solution (CON group) or Escherichia coli (E. coli) suspension (E. coli group) were injected into uterine horns. After eight days, in E. coli group severe acute endometritis was diagnosed, as well as decreased Y1R mRNA and protein abundances and Y2R mRNA abundance and increased Y2R protein abundance compared to CON group. NPY increased 5-LOX, LTAH and LTCS protein abundances and LTB4 and LTC4 release from the endometrial stripes of both groups, however in the E. coli group above parameters were higher compared to CON group. In both groups, Y1R antagonist reduced NPY-induced 5-LOX and LTCS protein abundances in reference to NPY influence alone. This effect was also exerted by Y1R antagonist combined with NPY on LTB4 release in the CON group and on LTAH protein abundance and LTC4 release in E. coli group. As compared to NPY action alone, Y2R antagonist with NPY caused a decrease in LTAH protein abundance and LTB4 and LTC4 release in both CON and E. coli groups. Summarizing, in the inflamed porcine endometrium changes Y1R and Y2R mRNA and protein abundances. NPY by interaction with Y1Rs and Y2Rs stimulates LTAH protein abundance and LTC4 release as well as acting through Y1Rs increases 5-LOX and LTCS protein abundances and by Y2Rs release LTB4. NPY, in an indirect manner, can affect the LT-regulated processes in an inflamed endometrium.