albumin - publications

Predict more albumin - ligand interactions now!

1. Am J Physiol Heart Circ Physiol. 2012 Apr 13. [Epub ahead of print]

PEG-Albumin supra plasma expansion is due to increased vessel wall shear stress
induced by blood viscosity shear thinning.

Sriram K, Tsai AG, Cabrales P, Meng F, Acharya SA, Tartakovsky DM, Intaglietta M.

1University of California, San Diego.

We study extreme hemodilution to a hematocrit (Hct) of 11% induced by three
plasma expanders: polyethylene glycol conjugated albumin (PEG-Alb), 6% Dextran 70
kDa, and 6% Dextran 500 kDa. The experimental component of our study relies on
the microelectrodes and cardiac output to measure both the rheological properties
of plasma-expander blood mixtures and the nitric oxide (NO) bioavailability in
vessel walls. The modeling component consists of an analysis of the distribution
of wall shear stress (WSS) in the microvessels. Our experiments demonstrate that
plasma expansion with PEG-Alb causes a state of supra-perfusion with cardiac
output 40% above baseline, significantly increases NO vessel-wall
bioavailability, and lowers peripheral vascular resistance. We attribute this
behavior to the shear thinning nature of blood and PEG-Alb mixtures. To
substantiate this hypothesis, we develop a mathematical model of non-Newtonian
blood flow in a vessel. Our model employs the Quemada rheological constitutive
relationship to express blood viscosity in terms of both Hct and shear rate. The
model reveals that the net effect of the hemodilution induced by relatively
low-viscosity shear-thinning PEG-Alb plasma expanders is to reduce overall blood
viscosity and to increase the WSS, thus intensifying endothelial NO production.
These changes act synergistically, significantly increasing cardiac output and
perfusion due to lowered overall peripheral vascular resistance.

PMID: 22505638 [PubMed - as supplied by publisher]