Byrd MaryKate H, Senn L Kirsten, Pasternak Alex, Stewart Kara R, Johnson Jay S
Department of Animal Sciences, Purdue University, West Lafayette, IN, 47907, USA.
Division of Animal Sciences, University of Missouri, Columbia, MO, 65201, USA.
Sci Rep. 2025 Jul 23;15(1):26730. doi: 10.1038/s41598-025-12698-w.
In utero heat stress (IUHS) alters hypothalamic-pituitary-adrenal (HPA) axis development in pigs; however, the mechanisms mediating this effect remain unclear. This study aimed to evaluate cortisol transfer dynamics from the heat-stressed (HS) dam to the IUHS conceptus during early gestation. We hypothesized that gestational HS would modify maternal cortisol secretion and increase conceptus cortisol exposure. Twenty-three gilts were exposed to thermoneutral (TN; n = 11) or HS (n = 12) conditions from gestation d 6 to 33. Maternal vaginal temperature, respiration rate, skin temperatures, and salivary cortisol concentrations were monitored. On d 33, dams were harvested to assess fetal and reproductive tract morphology and collect fetal and placental samples for glucocorticoid and 11β-HSD2 analyses. Heat-stressed gilts exhibited increased (P ≤ 0.01) vaginal temperature, respiration rate, and skin temperatures, but salivary cortisol was similar (P = 0.13). Total and viable fetuses per corpus luteum were reduced (P ≤ 0.05) in HS dams. Fetal tissue cortisone: cortisol tended to be reduced (P = 0.06) and was reduced in IUHS fetus amniotic fluid (P = 0.03). Amniotic fluid cortisone tended to decrease (P = 0.07), while cortisol tended to increase (P = 0.08) in IUHS fetuses. These data suggest IUHS increases fetal glucocorticoid exposure.
子宫内热应激（IUHS）会改变猪下丘脑 - 垂体 - 肾上腺（HPA）轴的发育；然而，介导这种效应的机制仍不清楚。本研究旨在评估妊娠早期热应激（HS）母猪向IUHS胚胎的皮质醇转移动态。我们假设妊娠期热应激会改变母体皮质醇分泌并增加胚胎的皮质醇暴露。23头后备母猪在妊娠第6天至33天暴露于热中性（TN；n = 11）或热应激（HS；n = 12）条件下。监测母体阴道温度、呼吸频率、皮肤温度和唾液皮质醇浓度。在第33天，处死母猪以评估胎儿和生殖道形态，并采集胎儿和胎盘样本进行糖皮质激素和11β - HSD2分析。热应激后备母猪的阴道温度、呼吸频率和皮肤温度升高（P≤0.01），但唾液皮质醇水平相似（P = 0.13）。热应激母猪每个黄体的总胎儿数和存活胎儿数减少（P≤0.05）。胎儿组织可的松：皮质醇有降低趋势（P = 0.06），IUHS胎儿羊水内的该比值降低（P = 0.03）。IUHS胎儿羊水内可的松有降低趋势（P = 0.07），而皮质醇有升高趋势（P = 0.08）。这些数据表明IUHS增加了胎儿的糖皮质激素暴露。
