Granulocyte-macrophage colony stimulating factor and interleukin-8 in the reproductive tract of ewes following oestrus and mating.

Cytokines produced in the female reproductive tract after mating may enhance reproductive success. The present study investigated the distribution of granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin (IL)-8 in tissues and luminal secretions from different sites in the reproductive tract of the ewe following oestrus and after natural mating. Fifteen ewes were mated with a ram for 1 h and their reproductive tracts collected 3, 6, 18, 24 or 48 h later. Another 15 ewes were used as oestrous controls. Luminal secretions and tissue samples were collected from seven sites in each reproductive tract. Secretions were analysed by enzyme-linked immunosorbent assay and tissues were stained immunohistochemically using anti-sheep GM-CSF and anti-sheep IL-8 antibodies. Both cytokines were found in luminal and glandular endometrial epithelium and, to a lesser extent, in cervical epithelium; neither was found in the vaginal epithelium. Twice as many (P < 0.05) luminal samples from mated ewes than non-mated ewes were positive for GM-CSF. The vaginal lumen contained significantly higher (P < 0.01) concentrations of IL-8 compared with other sites, irrespective of mating status. Significant differences (P < 0.05) were found in staining intensity of GM-CSF and IL-8 from different sites. Production of GM-CSF and IL-8 by reproductive tissues is likely to contribute to leucocyte infiltration into the ovine reproductive tract.