title: The mechanism of the polymer-induced drag reduction in blood.
abstract: Literature reports provide evidence that nanomolar concentrations of spaghetti-like, high molecular weight polymers decrease the hydrodynamic resistance of blood thereby improving impaired blood circulation. It has been suggested that the polymer-induced drag reduction is caused by the corralling of red blood cells (RBCs) among extended macromolecules aligned in the flow direction. This mechanism predicts that drag-reducing polymers must affect the conductivity of completely dispersed blood, time-dependent and steady state structural organization of aggregated RBCs at rest. However, experimental results obtained at the concentration of poly(ethylene oxide) (PEO, MW=4 × 10(6)) of 35 ppm show that neither the conductivity of completely dispersed blood, nor the kinetics of RBC aggregation occurring after the stoppage of flow, nor the structural organization of aggregated RBCs in the quiescent blood are affected by PEO. As these results are at odds with the "corralling" hypothesis, it is assumed that the effect of these polymers on the drag is associated with their interactions with local irregularities of disturbed laminar blood flow.
authors.affiliation: Experimental Hematology Laboratory, Physiology Department, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel. alexp@bgu.ac.il
authors.forename: Alexander
authors.initials: A
authors.lastname: Pribush
authors.forename: Lev
authors.initials: L
authors.lastname: Hatzkelzon
authors.forename: Dan
authors.initials: D
authors.lastname: Meyerstein
authors.forename: Naomi
authors.initials: N
authors.lastname: Meyerstein
mesh_terms: D004553:Electric Conductivity; D004912:Erythrocytes / Q000187:drug effects* / Q000502:physiology*; D006439:Hemodynamics / Q000187:drug effects*; D018056:Hemorheology / Q000187:drug effects; D006801:Humans; D011092:Polyethylene Glycols / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D011092:Polyethylene Glycols