EN
The aim of the study was to establish the effect of the ovarian steroids: 17β-oestradiol (E2) and testosterone (T4) on OT-stimulated PGF2α and PGE2 secretion by bovine endometrial cells. The epithelial endometrial cells from days 14-18 of the oestrous cycle (10⁵/ml) were incubated in DMEM/Ham's F12 with 10% FCS (38°C, atmosphere of air and 5% CO₂) for 72-96 h and the last 24 h in DMEM/Ham's F12 with 0.1% BSA. In Exp.l, the doses of steroids used to study their effect on the secretion of PGF2α and PGE2 from endometrial cells stimulated by OT were determined. In Exp.2, the cells were pre-incubated for 30 min with selected doses of steroids: P4 (10⁻⁵ M), T4 (10⁻⁵ M), and E2 (10⁻⁸ M) and next for 4 d with: arachidonic acid (AA; 10⁻⁵ M), OT (10⁻⁷ M) and OT with each of these steroids. The concentration of PGE2 and PGFM -metabolite of PGF2α was determined by EIA. P4, T4, and E2 did not affect (P>0.05) the basal secretion of PGF2α and PGE2, but all the steroids inhibited (P<0.01) OT- stimulated PGF2α secretion. The stimulating effect of OT on PGE2 secretion was not affected by P4 and T4 (P>0.05). This data suggests that different cellular mechanisms exist for steroids affecting the secretion of both prostaglandins from endometrial cells. Moreover, we suggest that non-genomic effect of P4 on bovine endometrial cells is non-specific since the other steroids can impair the effect of OT on these cells. This effect of the steroids can directly modulate function of endometrial cells.