Reproductive Unit of the Clinics - Clinic for Small Animals, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany.
Reproductive Unit of the Clinics - Clinic for Small Animals, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany; Department of Veterinary Clinical Sciences, Section of Veterinary Reproduction and Obstetrics, University of Copenhagen, Copenhagen, Denmark.
Theriogenology. 2021 Nov;175:134-147. doi: 10.1016/j.theriogenology.2021.09.003. Epub 2021 Sep 10.
Prostaglandin (PG) E2 plays a crucial role in the endocrine network of canine parturition and we hypothesized that PGE2, 15-hydroxyprostaglandin dehydrogenase (HPGD) and PG-transporter (PGT) might be involved in the development of primary uterine inertia (PUI). We investigated PTGE synthase (PTGES), PTGE receptors 2/4 (PTGER2/4), HPGD and PGT expression on the mRNA- and protein-level in interplacental (IP) and uteroplacental (UP) tissues of bitches presented with dystocia undergoing emergency caesarean section. Groups were formed retrospectively based on strict criteria: PUI (n = 12; small/normal/large litter - PUI-S/N/L: n = 5/4/3), and obstructive dystocia (OD, n = 8). Respective mRNA expressions (ratio) between PUI and OD in IP and UP, between PUI dogs with different litter sizes, between PUI-N and OD in IP, and overall between IP and UP were compared. PTGES, PTGER2, PTGER4, HPGD and PGT mRNA expressions did not differ significantly between PUI and OD in IP or UP. PUI-N PTGES mRNA expression was higher than PUI-S/L (P = 0.0203/P = 0.0186) and OD (P = 0.0314). Higher PTGES (P = 0.0112) and a tendency for higher PTGER2 (P = 0.059) mRNA-expressions were detected in UP versus IP. Other than hypothesized, we did not find a difference in PGE2 production and signaling between PUI and OD, indicating that altered uterine PTGES, PTGER2, PTGER4, HPGD and PGT expression was likely not causative for PUI. However, higher PTGES expression in PUI-N compared to OD might point to a possible role of PGE2 during the course of parturition. Higher PTGES expression in PUI-N compared to PUI-S/L indicates an influence of litter size, the underlying cause and biological relevance of which remain to be clarified.
前列腺素（PG）E2 在犬分娩的内分泌网络中起着至关重要的作用，我们假设 PGE2、15-羟基前列腺素脱氢酶（HPGD）和 PG 转运体（PGT）可能参与原发性子宫无力（PUI）的发展。我们研究了胎盘间（IP）和胎盘（UP）组织中前列腺素 E 合酶（PTGES）、前列腺素 E 受体 2/4（PTGER2/4）、HPGD 和 PGT 的 mRNA 和蛋白质水平表达，这些组织来自于因难产而接受紧急剖腹产的母犬。根据严格的标准回顾性地分组：原发性子宫无力（PUI，n=12；小/正常/大窝产仔-PUI-S/N/L：n=5/4/3）和梗阻性难产（OD，n=8）。比较 IP 和 UP 中 PUI 和 OD 之间、不同窝产仔大小的 PUI 犬之间、PUI-N 和 OD 之间以及 IP 和 UP 之间的相应 mRNA 表达（比值）。在 IP 或 UP 中，PUI 和 OD 之间、IP 和 UP 之间的 PTGES、PTGER2、PTGER4、HPGD 和 PGT mRNA 表达无显著差异。PUI-N 的 PTGES mRNA 表达高于 PUI-S/L（P=0.0203/P=0.0186）和 OD（P=0.0314）。在 UP 中检测到较高的 PTGES（P=0.0112）和 PTGER2 （P=0.059）mRNA 表达的趋势。与假设相反，我们没有发现 PUI 和 OD 之间 PGE2 产生和信号转导的差异，这表明 PUI 中子宫 PTGES、PTGER2、PTGER4、HPGD 和 PGT 表达的改变可能不是 PUI 的原因。然而，与 OD 相比，PUI-N 中 PTGES 的表达更高，这可能表明 PGE2 在分娩过程中可能发挥作用。与 PUI-S/L 相比，PUI-N 中 PTGES 的表达更高，表明窝产仔数的影响，其潜在原因和生物学相关性仍有待阐明。
