Levin D L, Heymann M A, Rudolph A M
Circulation. 1979 Jan;59(1):179-82. doi: 10.1161/01.cir.59.1.179.
The main pulmonary trunk was banded in four fetal sheep at 63--69 days of gestation. The fetuses were killed after they had developed progressive pulmonary stenosis at 98, 123, 134 and 135 days of gestation. The right lung of each animal was perfused with glutaraldehyde and serial sections followed microscopically. The medial width/external diameter ratios for fifth generation resistance vessels were significantly less (0.13) than those from six normal control lungs (0.16, p less than 0.001). In addition, the number of resistance vessels per cm2 lung tissue in the lungs of the animals with experimental pulmonic stenosis was less than in normal controls. The altered in utero hemodynamics with severe pulmonic stenosis results in thin-walled pulmonary arterial vessels. This may be caused by an increased blood oxygen tension of the blood perfusing the pulmonary circulation via reversed flow through the ductus arteriosus, or altered pulmonary arterial pressure characteristics in the pulmonary vessels distal to the obstructed pulmonary trunk.
在妊娠63 - 69天的四只胎羊中对主肺动脉进行结扎。这些胎儿在妊娠98、123、134和135天时出现进行性肺动脉狭窄后被处死。每只动物的右肺用戊二醛灌注，并进行系列切片显微镜观察。第五代阻力血管的内侧宽度/外径比值（0.13）显著低于六个正常对照肺（0.16，p < 0.001）。此外，实验性肺动脉狭窄动物肺中每平方厘米肺组织的阻力血管数量少于正常对照。子宫内严重肺动脉狭窄导致的血流动力学改变致使肺动脉血管壁变薄。这可能是由于通过动脉导管逆流灌注肺循环的血液血氧张力增加，或者是阻塞的肺动脉主干远端肺血管内肺动脉压力特征改变所致。
