It is widely agreed that only the severe and prolonged exposure to stressors, connected with significant and long–term increment in plasma cortisol concentration can suppress reproduction in female pigs. Therefore, the aim of the present study was to check the effect of acute stress-like concentrations of cortisol on oestrogens (17β-oestradiol – E-2, oestrone – E-1) and progesterone (P-4) secretion by porcine granulosa cells isolated from 6-7 mm in diameter ovarian follicles. The granulosa cells were cultured in serum free – DMEM/F 12 medium (1:1) supplemented with testosterone (10^-7 M/l) and gentamicin (20 μg/ml) without cortisol (control) or with 2,8 × 10^-7, 10^-6, 10^-5 and 10^-4 mM/l of cortisol, respectively. After 6 and 12 h of the culture, medium was collected to analyse the concentration of secreted E-2, E-1 and P-4 by HPLC method. Oestrogen and progesterone secretion was expressed as a quantity of hormone, which was released to 1 ml of culture medium by about 5 × 10⁵ granulosa cells during 6 and 12 h, respectively. The proliferation of cells was estimated using MTT test. The obtained results show that cortisol, independently of the used concentration (2.8 × 10^-7 – 2.8 × 10^-4 M/l) caused the significant (P≤0.05) suppression in E-2 and E-1 secretion from porcine granulosa cells in vitro, both after 6 and 12 h of culture. Indeed, the effect of cortisol on progesterone secretion from porcine granulosa cells was dependent on the used dose. Contrary to oestrogens, the increment in P-4 secretion under the influence of 2.8 × 10^-7 – 2.8 × 10^-5 M/l of cortisol was observed. There was found very high positive correlation between P-4 and cortisol dose in this range (r=0.81 after 6h, r=0.72 after 12 h). However, the highest dose of cortisol (2.8 x 10^-4 M/l) caused the drop in P-4 secretion (23.45 ± 1.18 pg/ml/5 × 10⁵ granulosa cells/12 h) in comparison to control (40.63 ± 2.85 pg/ml/5 × 10⁵ granulosa cells/12 h).

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