Vilos G A, Challis J R, Lye S J, Possmayer F, Harding P G
Department of Obstetrics and Gynecology, St. Joseph's Hospital, University of Western Ontario, London, Canada.
Am J Obstet Gynecol. 1988 Dec;159(6):1321-6. doi: 10.1016/0002-9378(88)90549-2.
To examine the role of parturition on lung maturation in sheep, we studied parameters of lung development in singleton fetuses treated with pulsatile adrenocorticotropic hormone or saline solution from day 127 or twin pregnancies in which one fetus only received pulsatile adrenocorticotropic hormone from day 127 until labor occurred. These parameters were compared with those of term fetuses (145 days). Pulsatile adrenocorticotropic hormone provoked labor in a mean (+/- SEM) of 102.6 +/- 6.6 and 181.0 +/- 18.0 hours in single and twin pregnancies, respectively. Adrenal/body weight ratios increased similarly in adrenocorticotropic hormone-treated single and twin fetuses at delivery, and basal cortisol levels were two- to threefold higher prepartum in adrenocorticotropic hormone-treated fetuses. Little change in plasma cortisol levels occurred in singletons treated with saline solution or in twins not infused with adrenocorticotropic hormone. The lung weight/body weight was not altered in any group. Lung distensibility and stability were doubled to term values in fetuses treated with pulsatile adrenocorticotropic hormone compared with controls and untreated twins. Mean lavage phosphatidylcholine levels rose from 0.07 to 0.11 mg/gm in saline solution-treated or untreated fetuses to 0.20 to 0.23 mg/gm in pulsatile adrenocorticotropic hormone-treated singletons or twins, compared with 0.63 mg/gm at term. Phosphatidylcholine production increased from 0.51 dpm/gm/hr in saline solution-treated fetuses to 0.73 and 0.89 dpm/gm/hr in the single and twin pulsatile adrenocorticotropic hormone-infused fetuses, respectively; phosphatidylcholine production was 0.62 dpm/gm/hr in the noninfused twin. Lungs of twins treated with pulsatile adrenocorticotropic hormone were morphologically more mature than those of untreated twins. We conclude that fetal endocrine responses to exogenous adrenocorticotropic hormone, rather than the stimuli associated with labor per se, are responsible for lung maturation in the fetal sheep.
为研究分娩在绵羊肺成熟过程中的作用，我们对单胎胎儿或双胎妊娠胎儿的肺发育参数进行了研究。在单胎妊娠中，从第127天起用脉冲式促肾上腺皮质激素或生理盐水处理；在双胎妊娠中，从第127天起，其中一个胎儿仅接受脉冲式促肾上腺皮质激素直至分娩。将这些参数与足月胎儿（145天）的参数进行比较。脉冲式促肾上腺皮质激素分别使单胎和双胎妊娠平均（±标准误）在102.6±6.6小时和181.0±18.0小时发动分娩。在分娩时，促肾上腺皮质激素处理的单胎和双胎胎儿的肾上腺/体重比均有相似增加，且促肾上腺皮质激素处理的胎儿产前基础皮质醇水平高出两到三倍。用生理盐水处理的单胎或未注入促肾上腺皮质激素的双胎胎儿血浆皮质醇水平变化不大。任何一组的肺重量/体重均未改变。与对照组和未处理的双胎相比，用脉冲式促肾上腺皮质激素处理的胎儿肺扩张性和稳定性增加一倍，达到足月时的值。生理盐水处理或未处理的胎儿平均灌洗卵磷脂水平从0.07升至0.11mg/g，而促肾上腺皮质激素处理的单胎或双胎胎儿则从0.20升至0.23mg/g，足月时为0.63mg/g。卵磷脂生成从生理盐水处理的胎儿的0.51dpm/g/hr分别增加到注入促肾上腺皮质激素的单胎和双胎胎儿的0.73和0.89dpm/g/hr；未注入的双胎为0.62dpm/g/hr。用脉冲式促肾上腺皮质激素处理的双胎胎儿的肺在形态上比未处理的双胎更成熟。我们得出结论，胎儿对外源性促肾上腺皮质激素的内分泌反应，而非分娩本身相关的刺激，是胎儿绵羊肺成熟的原因。
