Effect of cerebral hypothermia on cortisol and adrenocorticotropic hormone responses after umbilical cord occlusion in preterm fetal sheep
Effect of cerebral hypothermia on cortisol and adrenocorticotropic hormone responses after umbilical cord occlusion in preterm fetal sheep
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DOI：
10.1203/pdr.0b013e31815b8eb4
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发表时间：
2008-01-01
影响因子：
3.6
通讯作者：
Bennet, Laura
中科院分区：
文献类型：
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作者：
Davidson, Joanne O.;Fraser, Mhoyra;Bennet, Laura
下丘脑-垂体-肾上腺（HPA）轴是适应压力的关键。在本研究中，我们检验了头部冷却伴轻度全身低温会对胎儿促肾上腺皮质激素（ACTH）和皮质醇对窒息性损伤的反应产生不利影响的假设。慢性内固定早产胎羊（孕104 d，足月147 d）分为假脐带阻断组（n = 7）、脐带完全阻断25 min组（n = 7）、脐带阻断+头部降温+轻度全身低温组（n = 7（n = 7，平均+/- SEM食管温度37.6 +/- 0.3 ℃ vs 39.0 +/- 0.2 ℃; p < 0.05），从闭塞后90分钟至70小时，随后自发复温。在脐带阻塞期间，ACTH和皮质醇水平迅速升高，在脐带阻塞解除后进一步升高。在两个闭塞组中，ACTH水平在10小时后恢复到假手术对照值。与此相反，血浆皮质醇水平在两个闭塞组48小时后仍显着升高，并仍然显着升高，在低氧闭塞组复温后2小时，在72小时，与常温闭塞和假手术组相比。总之，低温不影响早产儿重度窒息时HPA的整体反应，但延长了皮质醇的反应。
The hypothalamic-pituitary-adrenal (HPA) axis is essential for adaptation to stress. In the present study, we examined the hypothesis that head cooling with mild systemic hypothermia would adversely affect fetal adrenocorticotropic hormone (ACTH) and cortisol responses to an asphyxial insult. Chronically instrumented preterm fetal sheep (104 d of gestation, term is 147 d) were allocated to sham occlusion (n = 7), 25 min of complete umbilical cord occlusion (n = 7), or occlusion and head cooling with mild systemic hypothermia (n = 7, mean +/- SEM esophageal temperature 37.6 +/- 0.3 degrees C vs 39.0 +/- 0.2 degrees C; p < 0.05) from 90 min to 70 h after occlusion, followed by spontaneous rewarming. During umbilical cord occlusion, there was a rapid rise in ACTH and cortisol levels, with further increases after release of cord occlusion. ACTH levels returned to sham control values after 10 h in both occlusion groups. In contrast, plasma cortisol levels remained elevated after 48 h in both occlusion groups and were still significantly elevated in the hypothermia-occlusion group 2 h after rewarming, at 72 h, compared with the normothermia-occlusion and sham groups. In conclusion, hypothermia does not affect the overall HPA responses to severe asphyxia in the preterm fetus but does prolong the cortisol response.