Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA.
Domest Anim Endocrinol. 2010 Feb;38(2):75-85. doi: 10.1016/j.domaniend.2009.08.006. Epub 2009 Sep 18.
Porcine corpora lutea (CL) fail to show a luteolytic response to prostaglandin-F-2alpha (PGF-2alpha) (ie, luteolytic sensitivity [LS]) until about day 12-13 of the estrous cycle. Although little is known of the control of LS in any species, endothelin-1 (EDN1) is believed to play a role in LS control in ruminants. Therefore, we measured mRNA and protein expression and examined the cellular localization of EDN1 precursor (pre-pro EDN1, or ppEDN1), EDN-converting enzyme-1 (ECE1), and EDN receptors (A, EDNRA and B, EDNRB) in porcine CLs collected on days 4, 7, 10, 13, and 15 of the estrous cycle to look for differences between CLs displaying (days 13-15) versus those lacking (days 4-10) LS. Abundance of ppEDN1 mRNA was greatest (and significant vs all other days) on day 7 of the cycle, whereas EDN1 protein expression did not vary during the cycle and was localized exclusively to endothelial cells (EC). Abundance of ECE1 mRNA was also greatest on day 7 (vs all other days), but ECE1 protein was significantly elevated on day 10 (vs day 4) and was immunolocalized to ECs and large luteal cells (LLC). Abundance of EDNRA mRNA was also maximal on day 7 (vs all other days) of the cycle, whereas EDNRA protein expression was not significantly changed during the cycle and was observed in LLCs, ECs, and small luteal cells (SLC). On day 13, EDNRB mRNA was significantly decreased (versus day 7). Expression of EDNRB protein was decreased on day 10 (versus all other days), and on days 13-15 (vs day 4), and was primarily localized to ECs. In conclusion, the observed elevation in ECE1 protein concentrations on day 10 and the presence of EDNRA on LLC suggests a possible role for EDN1 (resulting from the actions of ECE1) acting via EDNRA in the control of LS in the pig.
猪的黄体（CL）在发情周期的第 12-13 天之前对前列腺素 F-2alpha（PGF-2alpha）没有表现出溶黄体反应（即溶黄体敏感性[LS]）。尽管我们对任何物种的 LS 控制知之甚少，但内皮素-1（EDN1）被认为在反刍动物的 LS 控制中发挥作用。因此，我们测量了发情周期第 4、7、10、13 和 15 天采集的猪 CL 中的 EDN1 前体（前脯氨酸 EDN1，或 ppEDN1）、EDN 转化酶-1（ECE1）和 EDN 受体（A、EDNRA 和 B、EDNRB）的 mRNA 和蛋白表达，并检查了它们的细胞定位，以寻找具有 LS（第 13-15 天）和缺乏 LS（第 4-10 天）的 CL 之间的差异。ppEDN1 mRNA 的丰度在周期的第 7 天最高（与所有其他天数相比均有显著差异），而 EDN1 蛋白表达在周期内没有变化，仅定位于内皮细胞（EC）。ECE1 mRNA 的丰度也在第 7 天最高（与所有其他天数相比），但 ECE1 蛋白在第 10 天（与第 4 天相比）显著升高，并免疫定位到 EC 和大黄体细胞（LLC）。EDNRA mRNA 的丰度也在周期的第 7 天（与所有其他天数相比）达到最大值，而 EDNRA 蛋白表达在周期内没有显著变化，并在 LLC、EC 和小黄体细胞（SLC）中观察到。第 13 天，EDNRB mRNA 明显下降（与第 7 天相比）。EDNRB 蛋白的表达在第 10 天（与所有其他天数相比）和第 13-15 天（与第 4 天相比）下降，主要定位于 EC。总之，第 10 天 ECE1 蛋白浓度升高和 LLC 中存在 EDNRA 表明，EDN1（由 ECE1 作用产生）可能通过 EDNRA 在猪 LS 的控制中发挥作用。
