Glenny R W, Polissar N L, McKinney S, Robertson H T
Department of Medicine, University of Washington, Seattle 98191, USA.
J Appl Physiol (1985). 1995 Sep;79(3):986-1001. doi: 10.1152/jappl.1995.79.3.986.
This study investigates temporal changes in regional pulmonary perfusion. Five dogs were studied with five or six different radiolabeled microspheres being injected via a central vein over 30 s every 20 min. The lungs of each animal were cubed into 1.9 cm3 pieces with spatial coordinates noted for each piece. Within individual pieces, the coefficient of variation of regional perfusion over time was 17.2 +/- 6.8% (SD) and across dogs accounted for 7.26 +/- 5.7% of total perfusion heterogeneity. Temporal variability or "twinkling" was not random. When lung pieces with similar temporal flow patterns were grouped together (regardless of spatial location), groups were more tightly clustered in space than expected by chance. Statistical clustering methods revealed regulation of blood flow on a large scale (lobar arteries), and fractal analyses suggested regulation existed on a smaller scale (arterioles). We conclude that regional pulmonary perfusion is heterogeneous over time in a nonrandom pattern and that pieces clustered by temporal patterns of perfusion are neighbors in the spatial domain.
本研究调查了肺局部灌注的时间变化。对5只狗进行了研究，每隔20分钟通过中心静脉在30秒内注射5或6种不同的放射性标记微球。将每只动物的肺切成1.9立方厘米的小块，并记录每块的空间坐标。在各个小块内，局部灌注随时间的变异系数为17.2±6.8%（标准差），在不同狗之间占总灌注异质性的7.26±5.7%。时间变异性或“闪烁”并非随机。当将具有相似时间血流模式的肺小块聚集在一起时（无论空间位置如何），这些组在空间上比随机预期的更紧密地聚集在一起。统计聚类方法揭示了在大尺度（叶动脉）上的血流调节，分形分析表明在较小尺度（小动脉）上也存在调节。我们得出结论，肺局部灌注随时间呈非随机模式的异质性，并且按灌注时间模式聚类的小块在空间域中是相邻的。
