Circulation Research, Vol 70, 1113-1121, Copyright © 1992 by American Heart Association

ARTICLES

Redistribution of red blood cell flow in microcirculatory networks by hemodilution

AR Pries, A Fritzsche, K Ley and P Gaehtgens
Department of Physiology, Freie Universitat Berlin, FRG.

The effect of isovolemic hemodilution on red blood cell flow distribution was studied in complete self-contained microvessel networks of the rat mesentery. Hematocrit, diameter, and length of all vessel segments as well as the topological structure were determined in control networks (systemic hematocrit, 0.54) and after hemodilution (systemic hematocrit, 0.30). Hemodilution was performed by exchanging blood with hydroxyethyl starch (MW 450,000; 6%) or homologous plasma. With hemodilution, the decrease of microvessel hematocrit exceeded that of systemic hematocrit. The average discharge hematocrit in capillaries was 79% of systemic hematocrit in the control group and 73% with hemodilution (p less than 0.001). The heterogeneity of capillary hematocrit within the network, expressed by the coefficient of variation, increased from 0.4 to 0.7. By using the morphological and topological data of four networks, the distribution of hematocrits was also calculated using a hydrodynamic flow model. The modeling results were found to be in close agreement with the experimental data. This indicates that the observed changes can be deduced from established rheological phenomena, most of all phase separation at arteriolar bifurcations. The changes in hematocrit distribution after hemodilution are accompanied by a redistribution of red blood cell flow within the network: relative to total red blood cell flow, red blood cell flow in the distal capillaries of the network increases by about 40% at the expense of the proximal capillaries that are close to the feeding arteriole and that exhibit the highest red blood cell flow under control conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				M. C. Barker, A. S. Golub, and R. N. Pittman Erythrocyte-associated transients in capillary PO2: an isovolemic hemodilution study in the rat spinotrapezius muscle Am J Physiol Heart Circ Physiol, May 1, 2007; 292(5): H2540 - H2549. [Abstract] [Full Text] [PDF]

				E. Mairey, A. Genovesio, E. Donnadieu, C. Bernard, F. Jaubert, E. Pinard, J. Seylaz, J.-C. Olivo-Marin, X. Nassif, and G. Dumenil Cerebral microcirculation shear stress levels determine Neisseria meningitidis attachment sites along the blood-brain barrier J. Exp. Med., August 7, 2006; 203(8): 1939 - 1950. [Abstract] [Full Text] [PDF]

				K. Rakusan, N. Cicutti, and F. Kolar Effect of anemia on cardiac function, microvascular structure, and capillary hematocrit in rat hearts Am J Physiol Heart Circ Physiol, March 1, 2001; 280(3): H1407 - H1414. [Abstract] [Full Text] [PDF]

				F. Bloos, C. M. Martin, C. G. Ellis, and W. J. Sibbald Effects of modest anemia on systemic and coronary circulation of septic sheep Am J Physiol Heart Circ Physiol, December 1, 1999; 277(6): H2195 - H2204. [Abstract] [Full Text] [PDF]

				A. G. Hudetz, J. D. Wood, B. B. Biswal, I. Krolo, and J. P. Kampine Effect of hemodilution on RBC velocity, supply rate, and hematocrit in the cerebral capillary network J Appl Physiol, August 1, 1999; 87(2): 505 - 509. [Abstract] [Full Text] [PDF]

				J. Hutter, O. Habler, M. Kleen, M. Tiede, A. Podtschaske, G. Kemming, C. Corso, S. Batra, P. Keipert, S. Faithfull, et al. Effect of acute normovolemic hemodilution on distribution of blood flow and tissue oxygenation in dog skeletal muscle J Appl Physiol, March 1, 1999; 86(3): 860 - 866. [Abstract] [Full Text] [PDF]

				A. R. Pries, T. W. Secomb, and P. Gaehtgens Design Principles of Vascular Beds Circ. Res., November 1, 1995; 77(5): 1017 - 1023. [Abstract] [Full Text]