Regional heterogeneity of lung blood flow is measured by analyzing the relative dispersion (RD) of mass (weight)-flow data. Pulmonary blood flow is fractal in nature and can be characterized by the fractal dimension (D) and RD for the smallest realizable volume element (piece size) termed RDref. Although information exists for the applicability of fractal analysis to pulmonary blood flow in whole animal models, little is known in isolated organs. Four different radiolabeled microspheres (141Ce, 95Nb, 85Sr, 51 Cr; 15μ were injected into the pulmonary lobar artery of isolated canine lungs (n=5) perfused at four flow rates (Flow 1 - 0.42 ±0.02 L/min; Flow 2 = 1.12±0.07 L/min; Flow 3 = 2.25±0.17 L/min; Flow 4 = 2.59±0.17 L/min) and the pulmonary blood flow distribution was measured. Results indicate that under normal blood flow (Flow 1) conditions, all regions of horizontally perfused isolated lungs received blood flow that was preferentially distributed to the most caudal regions of the lung. Regional pulmonary blood flow was heterogeneous and fractal in nature as measured by RD. As flow rates increased, D values remained constant while RD decreased, reflecting more homogeneous blood flow distribution. At any given blood flow rate, high flow areas of the lung received a proportionally larger amount of regional flow suggesting that the degree of pulmonary vascular recruitment may also be region specific. Supported by NIH HI.-47926, HL-45025. HL-31422, and the AHAGeorgia Affiliate, Inc.
|Original language||English (US)|
|State||Published - Dec 1 1996|
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)
- Biochemistry, Genetics and Molecular Biology(all)
- Cell Biology