Journal of Applied Physiology, Vol 40, Issue 1 60-66, Copyright © 1976 by American Physiological Society
Augmentation of sickling process due to turbulent blood flow
P. D. Stein, H. N. Sabbah and A. K. Mandal
The purpose of this study was to determine if the fluid mechanical stresses
associated with turbulent blood flow can contribute to the sickling
process. Blood from seven patients with sickle cell disease was subjected
to intermediate and high levels of turbulent flow in vitro. Turbulence was
quantitated by hot film anemometry. Control samples showed 20 +/- 3%
sickled cells. Cells subjected to intermediate levels of turbulent flow
showed 26 +/- 4% sickling (P less than 0.01); and blood subjected to high
intensities of turbulence showed 31 +/- 4% sickling (P less than 0.01). A
quantitative count by electronmicroscopy, performed in one patient, showed
polymerization of the hemoglobin indicative of sickling in more cells
subjected to turbulence than in the control sample. A turbulence-reducing
agent, polyethylene oxide, diminished the augmentation of the sickling
process as it reduced turbulence at comparable Reynolds numbers. These
results support the hypothesis that a deleterious effect upon hemoglobin SS
erythrocytes may occur due to the mechanical stresses of turbulent flow.
The agitation associated with turbulent flow presumably modifies the
stabilizing factors of the intracellular colloidal solution of hemoglobin,
thereby contributing to sol-gel transformation. Such hydrodynamic stresses
may supplement the previously described factors which contribute to sickle
cell crises.
