Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima 10, 10-747 Olsztyn, Poland.
Prostaglandins Other Lipid Mediat. 2010 Jun;92(1-4):13-8. doi: 10.1016/j.prostaglandins.2010.01.002. Epub 2010 Feb 10.
The aim of these studies was to evaluate of the relationship between luteal concentrations of oxytocin (OT), noradrenaline (NA), progesterone (P4), oxytocin receptors (OT-R) and beta(2)-adrenoreceptors (beta(2)-R) gene expression and their protein level throughout the estrous cycle in cattle. Corpora lutea (CL) collected during days 1-5, 6-10, 11-16 and 17-21 of the estrous cycle were used in these studies. Concentrations of P4, OT and NA were determined in tissue extracts. Gene expression and protein level for OT-R and beta(2)-R were investigated by RT-PCR and Western blot, respectively. Luteal concentration of P4 was higher (P<0.01) on days 6-10 and 11-16 than during days 1-5 and 17-20 of the estrous cycle. Concentration of OT was the highest on days 1-5 and 6-10 of the estrous cycle. This concentration decreased (P<0.01) during days 11-16 reaching the lowest level (P<0.001) on days 17-20 as opposed to days 1-10 of the estrous cycle. Expression of OT-R mRNA was lower on days 6-16 (P<0.05) followed by its increase on days 17-20 as opposed to the expression observed on days 1-5. Expression of OT-R mRNA was negatively correlated (P<0.05) with the profile of OT-R protein level. This latter parameter was the lowest on days 17-20 and 1-5, and the highest on days 6-10 and 11-16. Oxytocin concentration was negatively correlated (P<0.05) with expression of OT-R mRNA and positively correlated (P<0.001) with OT-R protein level. This protein level was only correlated with P4 (r=0.59; P<0.05). Concentration of OT was positively correlated with level of P4 (P<0.001). Concentration of NA was the highest on days 1-5 of the estrous cycle, whereas it was similar or lower (P<0.05) on days 6-21. Expression of mRNA for beta(2)-R was the lowest on days 1-5 and was highly increased (P<0.05) on days 6-16. The expression was the highest (P<0.001) on days 17-21 compared to all others group of the estrous cycle. Protein level for beta(2)-R was the highest on days 1-5 and decreased (P<0.05) on days 6-10 and 11-16. The expression was the lowest on days 17-20 compared to the beta(2)-R protein level in CL from all others stages of the estrous cycle. Protein level for beta(2)-R was positively correlated (P<0.05) with the OT concentration. Expression of mRNA for beta(2)-R was negatively correlated (P<0.001) with level of beta(2)-R protein. No correlation was found between beta(2)-R mRNA expression and NA concentration or between NA and P4 concentrations. Results presented in this study suggest an evident relationship between OT and NA and may play an important role in the regulation of luteal steroidogenesis during all stages of the estrous cycle.
这些研究的目的是评估在牛发情周期的各个阶段黄体中催产素（OT）、去甲肾上腺素（NA）、孕酮（P4）、催产素受体（OT-R）和β2-肾上腺素受体（β2-R）基因表达及其蛋白水平之间的关系。在发情周期的第 1-5 天、第 6-10 天、第 11-16 天和第 17-21 天采集黄体用于这些研究。组织提取物中测定 P4、OT 和 NA 的浓度。通过 RT-PCR 和 Western blot 分别研究 OT-R 和 β2-R 的基因表达和蛋白水平。黄体中 P4 的浓度在发情周期的第 6-10 天和第 11-16 天较高（P<0.01），而在第 1-5 天和第 17-20 天较低。OT 的浓度在发情周期的第 1-5 天和第 6-10 天最高。这一浓度在第 11-16 天下降（P<0.01），在第 17-20 天达到最低水平（P<0.001），而与发情周期的第 1-10 天相比。OT-R mRNA 的表达在第 6-16 天较低（P<0.05），随后在第 17-20 天增加，与第 1-5 天观察到的表达相反。OT-R mRNA 的表达与 OT-R 蛋白水平的变化呈负相关（P<0.05）。后者在第 17-20 天和第 1-5 天最低，在第 6-10 天和第 11-16 天最高。OT 浓度与 OT-R mRNA 的表达呈负相关（P<0.05），与 OT-R 蛋白水平呈正相关（P<0.001）。这一蛋白水平仅与 P4 相关（r=0.59；P<0.05）。OT 浓度与 P4 水平呈正相关（P<0.001）。NA 的浓度在发情周期的第 1-5 天最高，而在第 6-21 天相似或较低（P<0.05）。β2-R mRNA 的表达在第 1-5 天最低，在第 6-16 天显著增加（P<0.05）。在第 17-21 天表达最高（P<0.001），与发情周期的其他组相比。β2-R 蛋白水平在第 1-5 天最高，在第 6-10 天和第 11-16 天下降（P<0.05）。在第 17-20 天与发情周期的其他阶段的黄体中β2-R 蛋白水平相比，表达最低。β2-R 蛋白水平与 OT 浓度呈正相关（P<0.05）。β2-R mRNA 的表达与β2-R 蛋白水平呈负相关（P<0.001）。β2-R mRNA 表达与 NA 浓度或 NA 与 P4 浓度之间没有相关性。本研究的结果表明 OT 和 NA 之间存在明显的关系，可能在发情周期的各个阶段黄体甾体生成的调节中发挥重要作用。
