Influence of oestradiol-17 beta on interleukin-1 secretion by endotoxin-stimulated porcine mononuclear cells in vitro.

A bioassay for porcine interleukin-1 (IL-1) was validated. By use of this bioassay, the influence of increasing concentrations of oestradiol-17 beta on IL-1 secretion by endotoxin-stimulated porcine mononuclear cells (MNC) in vitro was studied. Supernatants from cultures of porcine MNC stimulated with LPS (0.1-10 micrograms/ml) induced a proliferative response in the IL-1 and IL-2 dependent cell line D10.G4.1 (D-10) in a dose-dependent manner with respect to LPS. Supernatants of LPS stimulated porcine MNC did not show any IL-2 activity in an bioassay for IL-2. Porcine MNC were cultured in the presence of increasing concentrations of oestradiol-17 beta (42-1500 pmol/l) and stimulated with LPS (10 micrograms/ml) or in the absence of oestradiol and LPS. The IL-1 secretion by the MNC, as determined by the D-10 bioassay, was significantly (P < 0.01) suppressed by the highest oestradiol concentration tested (1500 pmol/l). The results indicate that high physiological concentrations of oestradiol-17 beta may affect the secretion of IL-1 by porcine MNC.