Zimmermann Heiner, Gardner David S, Jellyman Juanita K, Fowden Abigail L, Giussani Dino A, Forhead Alison J
Department of Physiology, University of Cambridge, Downing Street, Cambridge CB2 3EG, United Kingdom.
Am J Obstet Gynecol. 2003 Nov;189(5):1467-71. doi: 10.1067/s0002-9378(03)00627-6.
The effect of dexamethasone on tissue angiotensin-converting enzyme (ACE) was investigated in fetal sheep.
Pulmonary and renal ACE concentrations were measured in 16 sheep fetuses at between 127 and 131 days of gestation (term 145+/-2 days): 6 were untreated, whereas 10 were chronically catheterized and infused intravenously with either saline solution (0.9%, n=4) or dexamethasone (45-60 microg. kg(-1). d(-1), n=6) for the previous 2 days. The dexamethasone dose increased plasma dexamethasone to around one fifth of that measured in newborn human infants delivered after maternal dexamethasone treatment.
Over the period of infusion, arterial blood pressure increased significantly in the dexamethasone (+6.8+/-1.5 mm Hg, P<.05) but not saline-treated fetuses (+1.6+/-0.6 mm Hg). At delivery, pulmonary ACE in the dexamethasone-infused fetuses (1.24+/-0.26 nmoles hippurate. min(-1). mg protein(-1)) was significantly greater than in the control fetuses (0.50+/-0.07 nmoles. min(-1). mg protein(-1), P<.005); renal ACE was unchanged by dexamethasone treatment. Overall, pulmonary ACE and blood pressure were correlated on the last day of infusion (r=0.70, P<.05).
The rise in pulmonary ACE seen in dexamethasone-treated sheep fetuses may contribute, in part, to the glucocorticoid-induced increase in blood pressure.
研究地塞米松对胎羊组织血管紧张素转换酶（ACE）的影响。
在妊娠127至131天（足月为145±2天）的16只胎羊中测量肺和肾的ACE浓度：6只为未治疗组，而10只进行了慢性导管插入术，并在之前2天经静脉输注生理盐水（0.9%，n = 4）或地塞米松（45 - 60μg·kg⁻¹·d⁻¹，n = 6）。地塞米松剂量使血浆地塞米松升高至母体接受地塞米松治疗后分娩的新生儿所测值的约五分之一。
在输注期间，地塞米松治疗组胎羊的动脉血压显著升高（+6.8±1.5 mmHg，P <.05），而生理盐水治疗组胎羊的动脉血压升高不显著（+1.6±0.6 mmHg）。分娩时氘代输注组胎羊的肺ACE（1.24±0.26纳摩尔马尿酸盐·分钟⁻¹·毫克蛋白⁻¹）显著高于对照组胎羊（对照组为0.50±0.07纳摩尔·分钟⁻¹·毫克蛋白⁻¹，P <.005）；地塞米松治疗对肾ACE无影响。总体而言，在输注的最后一天，肺ACE与血压相关（r = 0.70，P <.05）。
地塞米松治疗的胎羊肺ACE升高可能部分导致了糖皮质激素诱导的血压升高。
