Kondo M, Washizu M, Matsukura Y, Kobayashi K, Motoyoshi S, Miyasaka K, Takata M
Research Laboratory at Veterinary Medical Teaching Hospital, School of Veterinary Medicine, Nippon Veterinary and Animal Science University, Tokyo, Japan.
J Vet Med Sci. 1994 Feb;56(1):71-6. doi: 10.1292/jvms.56.71.
To analyze longitudinal distribution of pulmonary vascular resistance, we proposed a five element lumped model which partitioned pulmonary circulation into pulmonary arterial, middle and pulmonary venous segment. The validity and anatomical correlation of the model were tested in an isolated, perfused, canine lung lobe preparation with inflow/outflow occlusion techniques. With arterial occlusion, pulmonary arterial pressure fell rapidly and then exponentially. With venous occlusion, pulmonary venous pressure rose suddenly and then exponentially. Theoretical pressure profiles produced by computer simulation of the model well approximated the general characteristics of the experimental traces. Serotonin increased the pressure gradient across the pulmonary arterial segment (delta Pa), whereas histamine increased the gradient across the pulmonary venous segment (delta Pv). Neither drug altered the gradient across the middle segment (delta Pm). The results suggest that the lumped model is a useful concept to understand the longitudinal distribution of pulmonary vascular resistance, and that delta Pa, delta Pm and delta Pv reflect the resistance distribution of anatomical pulmonary arteries, alveolar vessels and pulmonary veins, respectively.
为分析肺血管阻力的纵向分布，我们提出了一个五元件集总模型，该模型将肺循环分为肺动脉段、中间段和肺静脉段。采用流入/流出阻断技术，在离体灌注犬肺叶标本中对该模型的有效性和解剖学相关性进行了测试。动脉阻断时，肺动脉压迅速下降，然后呈指数下降。静脉阻断时，肺静脉压突然升高，然后呈指数升高。通过对该模型进行计算机模拟得出的理论压力曲线很好地近似了实验曲线的一般特征。5-羟色胺增加了跨肺动脉段的压力梯度（ΔPa），而组胺增加了跨肺静脉段的梯度（ΔPv）。两种药物均未改变跨中间段的梯度（ΔPm）。结果表明，集总模型是理解肺血管阻力纵向分布的一个有用概念，且ΔPa、ΔPm和ΔPv分别反映了解剖学上肺动脉、肺泡血管和肺静脉的阻力分布。
