中文摘要：

目的研究地塞米松对宫内主动脉瓣球囊成形术（IUBAV）导致的胎羊应激反应的干预作用。方法 24只中晚期双胎妊娠山羊,随机分为对照组（n=12）及地塞米松组（n=12）。建立IUBAV模型,并在胎羊心腔内注射地塞米松,48只胎羊随之分为4组。术中及术后监测各组胎羊血糖、乳酸、肾上腺素、去甲肾上腺素、皮质醇、主动脉搏动指数（PI）及阻力指数（RI）,并于术前、术后3 h、3 d、新生羊15 d获取各组胎羊/新生羊血样及肝组织标本,检测血糖、乳酸、肾上腺素、去甲肾上腺素、皮质醇,以及胎羊肝糖原染色。结果 IUBAV导致胎羊血糖、乳酸、肾上腺素、去甲肾上腺素、皮质醇水平增高,pH值降低,术后3 h上述指标与术前相比差异均有统计学意义（P均〈0.05）;术后3 d,上述指标与术前相比差异仍有统计学意义（P均〈0.05）。地塞米松干预后,上述指标的变化被有效抑制。IUBAV术后,胎羊肝糖原明显消耗,术后3 d胎羊肝糖原逐渐恢复蓄积;地塞米松干预后,IUBAV术导致的糖原消耗减轻。IUBAV术后,胎羊主动脉RI增加,较术前差异有统计学意义（P〈0.05）;术后3 d有所降低,但与术前相比差异仍有统计学意义（P〈0.05）;地塞米松干预后,胎羊主动脉RI增高得到有效抑制。结论地塞米松干预能有效减轻IUBAV相关胎羊应激反应及RI增高。

英文摘要：

Objective To investigate the protective effect of dexamethasone on stress response induced by intrauterine balloon aortic valvuloplasty （IUBAV） in a fetal lamb model. Methods Twenty-four near term twin pregnant goats were randomly assigned to control group （n=12） and dexamethasone group （intracardiac injection of dexamethasone） （n=12）. Ultrasound guided IUBAV model was established. According to the combination of treatment and operation, 48 fetal lambs were divided into four groups. The following parameters were dynamically monitored by ultrasound, which were fetal and neonatal heart rate （HR）, cardiac rhythm, aortic resistance index （RI） and pulsatility index （PI）. On established IUBAV model, blood samples and liver tissue specimens were taken from fetal/neonatal goats for detection of blood glucose （Glu）, lactate acid （LA）, plasma epinephrine （E）, norepinephrine （NE）, cortisol （Cort）, hepatic glycogen staining. Results IUBAV resulted in increased values of Glu, LA, E, NE and Cort levels, and decreased pH value, there were significant differences between pre- and 3h-post procedure （P〈0.05）, and significant differences were also existed in these values between pre- and 3d-post procedure （P〈0.05）. After administrating dexamethasone, the changes of Glu, LA, E, NE, Cort and pH levels were suppressed effectively. Fetal hepatic glycogen was consumed in large amounts due to IUBAV while recovered 3 days after IUBAV by glycogen staining. After administrating dexamethasone, hepatic glycogen consumption related to IUBAV was obviously inhibited. After IUBAV, fetal aortic RI was increased, and there was significant differences compared with pre-procedure （P〈0.05）. Up to 3d-post procedure, the values of RI recovered to some extent, but statistical difference was exist- ed compared with pre-procedure （P〈0.05）. After administrating of dexamethasone, increased aortic RI was effectively sup- pressed. Conclusions IUBAV could lead to reversible stress response