Ziolkowska A, Mlynarczuk J, Kotwica J
Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima 10, 10-747 Olsztyn, Poland.
Pol J Vet Sci. 2013;16(2):231-9. doi: 10.2478/pjvs-2013-0033.
Cortisol stimulates the synthesis and secretion of oxytocin (OT) from bovine granulosa and luteal cells, but the molecular mechanisms of cortisol action remain unknown. In this study, granulosa cells or luteal cells from days 1-5 and 11-15 of the oestrous cycle were incubated for 4 or 8 h with cortisol (1 x 10(-5), 1 x 10(-7) M). After testing cell viability and hormone secretion (OT, progesterone, estradiol), we studied the effect of cortisol on mRNA expression for precursor of OT (NP-I/OT) and peptidyl glycine-alpha-amidating mono-oxygenase (PGA). The influence of RU 486 (1 x 10(-5) M), a progesterone receptor blocker and inhibitor of the glucocorticosteroid receptor (GR), on the expression for both genes was tested. Cortisol increased the mRNA expression for NP-I/OT and PGA in granulosa cells and stimulated the expression for NP-I/OT mRNA in luteal cells obtained from days 1-5 and days 11-15 of the oestrous cycle. Expression for PGA mRNA was increased only in luteal cells from days 11-15 of the oestrous cycle. In addition, RU 486 blocked the cortisol-stimulated mRNA expression for NP-I/OT and PGA in both types of cells. These data suggest that cortisol affects OT synthesis and secretion in bovine ovarian cells, by acting on the expression of key genes, that may impair ovary
皮质醇可刺激牛颗粒细胞和黄体细胞合成并分泌催产素（OT），但其作用的分子机制尚不清楚。在本研究中，将发情周期第1 - 5天和第11 - 15天的颗粒细胞或黄体细胞与皮质醇（1×10⁻⁵、1×10⁻⁷ M）孵育4或8小时。在检测细胞活力和激素分泌（OT、孕酮、雌二醇）后，我们研究了皮质醇对OT前体（NP - I/OT）和肽基甘氨酸α - 酰胺化单加氧酶（PGA）mRNA表达的影响。测试了孕酮受体阻滞剂和糖皮质激素受体（GR）抑制剂RU 486（1×10⁻⁵ M）对这两个基因表达的影响。皮质醇增加了颗粒细胞中NP - I/OT和PGA的mRNA表达，并刺激了发情周期第1 - 5天和第11 - 15天获得的黄体细胞中NP - I/OT mRNA的表达。PGA mRNA的表达仅在发情周期第11 - 15天的黄体细胞中增加。此外，RU 486阻断了两种类型细胞中皮质醇刺激的NP - I/OT和PGA的mRNA表达。这些数据表明，皮质醇通过作用于关键基因的表达来影响牛卵巢细胞中OT的合成和分泌，这可能会损害卵巢
