Raj J U, Chen P, Navazo L
Pediatr Res. 1986 Nov;20(11):1107-11. doi: 10.1203/00006450-198611000-00009.
We have reported the longitudinal distribution of vascular resistance in the three segments (arteries, microvessels, and veins) of the pulmonary circulation of adult rabbits (J Appl Physiol 60:539-545, 1986). To determine the longitudinal distribution of vascular resistance in lungs of younger animals, we measured microvascular pressures in the subpleural microcirculation in nine isolated blood perfused lungs of 3- to 4-wk-old rabbits. We used micropipettes and the servonull pressure measuring system to directly measure pressures in 20-50 microns diameter subpleural arterioles and venules. We also measured pulmonary arterioles and venules. We also measured pulmonary arterial and left atrial pressures and lung blood flow. To determine the influence of vascular tone on segmental vascular resistance, in four lungs we measured microvascular pressures both before and after paralyzing the vasculature with papaverine. We found that 51% of the total pressure drop in the pulmonary circulation was in arteries, 24.5% in microvessels, and 24.5% in veins. Vascular tone contributed minimally to baseline arterial resistance. The greater arterial and venous resistance in lungs of 3- to 4-wk-old rabbits as compared to that in adult rabbits is probably due to differences in vessel geometry.
我们已经报道了成年兔肺循环三个部分（动脉、微血管和静脉）血管阻力的纵向分布（《应用生理学杂志》60:539 - 545，1986年）。为了确定幼龄动物肺血管阻力的纵向分布，我们在9个3至4周龄兔的离体血液灌注肺的胸膜下微循环中测量了微血管压力。我们使用微量移液器和伺服零压力测量系统直接测量直径为20 - 50微米的胸膜下小动脉和小静脉中的压力。我们还测量了肺小动脉和小静脉。我们也测量了肺动脉和左心房压力以及肺血流量。为了确定血管张力对节段性血管阻力的影响，在4个肺中，我们在用罂粟碱使血管麻痹前后都测量了微血管压力。我们发现肺循环中总压力降的51%在动脉，24.5%在微血管，24.5%在静脉。血管张力对基线动脉阻力的贡献最小。与成年兔相比，3至4周龄兔肺中较大的动脉和静脉阻力可能是由于血管几何形状的差异。
