Steiner Marianne, Schuler Gerhard, Frehner Bianca L, Reichler Iris M, Goericke-Pesch Sandra, Balogh Orsolya, Tavares Pereira Miguel, Kowalewski Mariusz P
Institute of Veterinary Anatomy, Vetsuisse Faculty, University of Zurich, CH-8057 Zurich, Switzerland.
Clinic for Obstetrics, Gynecology and Andrology of Large and Small Animals, Justus-Liebig-University, 35392 Giessen, Germany.
Animals (Basel). 2025 Oct 20;15(20):3043. doi: 10.3390/ani15203043.
The canine parturition cascade involves decreased placental progesterone (P4) signaling mediated through its nuclear receptor PGR in decidual cells, leading to increased trophoblast production of PGF2α that promotes luteolysis, placentolysis, and myometrial contractility. A local role for glucocorticoids in initiating parturition through increased placental availability of cortisol and glucocorticoid receptor (/), possibly affecting P4-PGR signaling, has been suggested. Primary uterine inertia (PUI) is a major cause of canine dystocia, but its pathophysiology remains unclear. Here, we hypothesized that dysregulated placental signaling could contribute to PUI. The availability of parturition cascade-related factors was assessed in placentae of dogs with PUI and during physiological prepartum luteolysis (LUT). Compared with LUT, PUI had no significant changes in prostaglandin-related factors , , and ( > 0.05), but had lower PGF2α synthase / ( < 0.001), and higher abundance ( < 0.001). PUI had increased PGR transcript and protein levels ( < 0.001), but the same number of decidual cells ( > 0.05). / availability was reduced in PUI ( < 0.05), along with decreased placental cortisol-to-cortisone conversion. Our findings suggest that PUI could be associated with disturbances of the parturition cascade, possibly due to inadequate P4-PGR and glucocorticoid signaling in the placenta.
犬类分娩级联反应涉及蜕膜细胞中通过其核受体PGR介导的胎盘孕酮（P4）信号减少，导致滋养层产生的PGF2α增加，从而促进黄体溶解、胎盘溶解和子宫肌层收缩。有研究表明，糖皮质激素可能通过增加胎盘皮质醇和糖皮质激素受体（/）的可用性在启动分娩中发挥局部作用，这可能会影响P4-PGR信号传导。原发性子宫收缩乏力（PUI）是犬类难产的主要原因，但其病理生理学仍不清楚。在此，我们假设胎盘信号失调可能导致PUI。在患有PUI的犬类胎盘以及生理产前黄体溶解（LUT）期间，评估了分娩级联相关因子的可用性。与LUT相比，PUI中前列腺素相关因子、和没有显著变化（>0.05），但PGF2α合酶/较低（<0.001），而丰度较高（<0.001）。PUI的PGR转录本和蛋白水平增加（<0.001），但蜕膜细胞数量相同（>0.05）。PUI中/可用性降低（<0.05），同时胎盘皮质醇向可的松的转化率降低。我们的研究结果表明，PUI可能与分娩级联反应的紊乱有关，可能是由于胎盘中P4-PGR和糖皮质激素信号不足所致。
