不同剂量地塞米松对早产胎鼠肺成熟度及生长发育的影响

Study on the effects of various dosage of dexamethasone in accelerating fetal lung maturation and the accompanied side effects in rats

目的 探讨不同剂量的地塞米松促进胎鼠肺成熟的效果及其对孕鼠和仔鼠的影响。方法 6 0只定时受孕的Wistar大鼠 ,随机分为安慰剂组、小剂量组、中剂量组及大剂量组 4组 ,每组 15只。于妊娠第 15、16天分别给予如下处理 :安慰剂组孕鼠皮下注射生理盐水 0 8ml、小剂量组孕鼠皮下注射地塞米松 0 2mg、中剂量组孕鼠皮下注射地塞米松 0 4mg、大剂量组孕鼠皮下注射地塞米松0 8mg ,药物均分 4次皮下注射。妊娠 17d时 ,每组随机选择 10只孕鼠行剖宫术取胎 ,其余 5只孕鼠等待自然分娩。观察各组早产仔鼠的呼吸能力、肺组织学评分及羊水板层小体 (LB)记数 ,比较不同剂量的地塞米松对胎肺成熟的影响 ;观察孕鼠的围产期情况及仔鼠体重、肝脏和肾上腺结构等 ,比较不同剂量地塞米松对母、胎的副作用。结果 小剂量组、中剂量组及大剂量组仔鼠的 3种肺成熟度指标显著高于安慰剂组 (P <0 0 5 )。安慰剂组、小剂量组、中剂量组及大剂量组仔鼠的呼吸评分依次为1 4± 0 5、3 6± 0 7、4 2± 0 5及 4 5± 0 5 ;肺组织学评分依次为 1 4± 0 6、3 9± 0 9、4 2± 0 7及 4 4±0 6 ;羊水LB记数依次为 (8 6± 3 0 )× 10 9 ml、(30 2± 4 2 )× 10 9 ml、(33 0± 3 4 )× 10 9 ml及 (35 8±2 7)× 10 9

Objective To compare the effect of various dosage of dexamethasone (Dex) in accelerating fetal lung maturation and the accompanied side effects. Method Sixty time-bred Wistar rats were randomly assigned to one of the four groups(15 rats each group). They were given normal saline 0.8 ml (group A); Dex 0.2 mg (group B); Dex 0.4 mg (group C); Dex 0.8 mg (group D) IH, separated for 4 times on gestational day 15,16. ten rats in each group were killed and hysterotomys were made immediately on day 17. The neonate breathing scale and their lung were observed and scored; the amniotic lamerllar bodies (LB) were counted to assess the preterm fetal lung maturation. The remaining 5 rats in each group delivered naturally. The mother rats′ condition in perinatal period, the birth weight of their neonates, and the structure of the livers and adrenal glands of the neonates were recorded to assess the side effects of the drug. Results The scores of neonatal breathing scale in group A to D were: 1.4±0.5,3.6±0.7,4.2±0.5,4.5±0.5; their lung histologic maturation degree: 1.4±0.6,3.9±0.9,4.2±0.7,4.4±0.6; and the account of their amniotic LB were:(8.6±3.0),(30.2±4.2),(33.0±3.4),(35.8±2.7)×10~9/ml respectively. All the indexes in the three Dex groups were higher than group A, and there were no statistical difference among in the three Dex groups except the neonatal breathing scale scores, which were higher in the high dose group D than the low dose group B. When high dose Dex was used, there was a reductive tendency in mother rats weight and its ability to resist infectious disease; meanwhile, the birth weight of their neonates reduced , the number of stillbirth and neonate liver necrosis increased. Conclusion By the preterm gravid rat model, low dosage of antenatal dexamethasone administration accelerate fetal lung maturation to the extent equally to the middle even high doses of the drug. When high dosage of Dex was administered, the increasing side effects on the mother rats and their fetuses were accompanied.