Liggins G C, Vilos G A, Campos G A, Kitterman J A, Lee C H
J Dev Physiol. 1981 Aug;3(4):267-74.
The relationship of breathing movements to lung development in the ovine fetus was investigated by transecting the fetal cervical spinal cord above (C2-C3; n = 4) or below (C7-C8; n = 4) the phrenic nucleus at 114 days of gestation. The fetuses were delivered by hysterotomy at term and compared with a group of intact term fetuses (n = 8). Cord transection at C2-C3 resulted in a significant (P less than 0.05) reduction in wet weight of the lungs to 1.56 +/- 0.23% of body weight from 2.59 +/- 0.83% in the C7-C8 group. The diaphragms of the two groups did not differ in weight or histological appearance. Distensibility of the left lung with air at 40 cmH20 was significantly less in the C2-C3 group (6.8 +/- 3.5 ml.kg-1 body weight) than the C7-C8 group (19.9 +/- 3.7 ml.kg-1) or the intact controls (15.2 +/- 5.4 ml.kg-1). DNA content in the C2-C3 group (0.63 +/- 0.12 g) was less than in controls (0.99 +/- 0.19 g) but it was not different from the C7-C8 group (0.82 +/- 0.33 g.) DNA concentration, water content and saturated phosphatidylcholine concentration in lung tissue and lavage fluid were similar in the three groups. It is concluded that the absence of breathing movements caused by transection of the spinal cord above the phrenic nucleus is associated with retarded lung growth and maturation.
通过在妊娠114天时横断胎羊胎儿颈段脊髓来研究呼吸运动与肺发育之间的关系，横断部位分别在膈神经核上方（C2 - C3；n = 4）或下方（C7 - C8；n = 4）。足月时通过子宫切开术娩出胎儿，并与一组完整的足月胎儿（n = 8）进行比较。C2 - C3水平横断脊髓导致肺湿重显著降低（P < 0.05），从C7 - C8组占体重的2.59 ± 0.83%降至1.56 ± 0.23%。两组的膈肌在重量或组织学外观上无差异。在40 cmH₂O压力下，C2 - C3组左肺的空气扩张性（6.8 ± 3.5 ml·kg⁻¹体重）显著低于C7 - C8组（19.9 ± 3.7 ml·kg⁻¹）或完整对照组（15.2 ± 5.4 ml·kg⁻¹）。C2 - C3组的DNA含量（0.63 ± 0.12 g）低于对照组（0.99 ± 0.19 g），但与C7 - C8组（0.82 ± 0.33 g）无差异。三组肺组织和灌洗液中的DNA浓度、含水量和饱和磷脂酰胆碱浓度相似。结论是，在膈神经核上方横断脊髓导致呼吸运动缺失与肺生长和成熟延迟有关。
