This Article Full Text Full Text (PDF) All Versions of this Article: biophysj.104.047746v1 87/6/4259    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Armstrong, J. K. Articles by Fisher, T. C. Search for Related Content PubMed PubMed Citation Articles by Armstrong, J. K. Articles by Fisher, T. C.

The Hydrodynamic Radii of Macromolecules and Their Effect on Red Blood Cell Aggregation

Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California

Correspondence: Address reprint requests to J. K. Armstrong, Dept. of Physiology and Biophysics, Keck School of Medicine, University of Southern California, 1333 San Pablo St., Los Angeles, CA 90033. Tel.: 323-442-3387; Fax: 323-442-1617; E-mail: jkarmstr{at}usc.edu.

The effects of nonionic polymers on human red blood cell (RBC) aggregation were investigated. The hydrodynamic radius (R_h) of individual samples of dextran, polyvinylpyrrolidone, and polyoxyethylene over a range of molecular weights (1500–2,000,000) were calculated from their intrinsic viscosities using the Einstein viscosity relation and directly measured by quasi-elastic light scattering, and the effect of each polymer sample on RBC aggregation was studied by nephelometry and low-shear viscometry. For all three polymers, despite their different structures, samples with R_h <4 nm were found to inhibit aggregation, whereas those with R_h >4 nm enhanced aggregation. Inhibition increased with R_h and was maximal at 3 nm; above 4 nm the pro-aggregant effect increased with R_h. For comparison, the R_h of 12 plasma proteins were calculated from literature values of intrinsic viscosity or diffusion coefficient. Each protein known to promote RBC aggregation had R_h >4 nm, whereas those with R_h <4 nm either inhibited or had no effect on aggregation. These results suggest that the influence of a nonionic polymer or plasma protein on RBC aggregation is simply a consequence of its size in an aqueous environment, and that the specific type of macromolecule is of minor importance.

This article has been cited by other articles:

				B. Neu, R. Wenby, and H. J. Meiselman Effects of Dextran Molecular Weight on Red Blood Cell Aggregation Biophys. J., September 15, 2008; 95(6): 3059 - 3065. [Abstract] [Full Text] [PDF]

				S. Jin, Z. Zador, and A. S. Verkman Random-Walk Model of Diffusion in Three Dimensions in Brain Extracellular Space: Comparison with Microfiberoptic Photobleaching Measurements Biophys. J., August 15, 2008; 95(4): 1785 - 1794. [Abstract] [Full Text] [PDF]

				M. Kimura and S. Takemori CH2-Units on (Poly-)ethylene Glycol Radially Dehydrate Cytoplasm of Resting Skinned Skeletal Muscle J. Biochem., June 1, 2008; 143(6): 841 - 847. [Abstract] [Full Text] [PDF]

				Z. Liu, W. Weng, R. M. Bookchin, V. L. Lew, and F. A. Ferrone Free Energy of Sickle Hemoglobin Polymerization: A Scaled-Particle Treatment for Use with Dextran as a Crowding Agent Biophys. J., May 1, 2008; 94(9): 3629 - 3634. [Abstract] [Full Text] [PDF]

				M. Kimura and S. Takemori CH2-Units on (Poly-)ethylene Glycol Radially Dehydrate Cytoplasm of Resting Skinned Skeletal Muscle J. Biochem., January 1, 2008; 143(1): 123 - 129. [Abstract] [Full Text] [PDF]

				J. F. Hoffman and S. Inoue Directly observed reversible shape changes and hemoglobin stratification during centrifugation of human and Amphiuma red blood cells PNAS, February 21, 2006; 103(8): 2971 - 2976. [Abstract] [Full Text] [PDF]

				W. Yu, R. M. Sandoval, and B. A. Molitoris Quantitative intravital microscopy using a Generalized Polarity concept for kidney studies Am J Physiol Cell Physiol, November 1, 2005; 289(5): C1197 - C1208. [Abstract] [Full Text] [PDF]