title: Effect of procaine hydrochloride on the aggregation behavior and suspension viscoelasticity of human red blood cells.
abstract: The present study examined the effects of procaine hydrochloride (PRHCL), a cationic local anesthetic, on the aggregation behavior of human red blood cells (RBC); the effects of PRHCL on RBC suspension viscoelasticity, cell shape, volume and density were also investigated. Four indices of RBC aggregation, induced by autologous plasma or 3 g% dextran T70, were evaluated by a computerized light transmission method, and the viscous and elastic components of the complex viscosity were determined by oscillatory viscometry. Low concentrations of PRHCL (8 x 10(-5) to 8 x 10(-4) M) significantly (p less than 0.05 or better) reduced the extent of aggregation (maximal decrease of 22% at 8 x 10(-4) M), but did not alter the viscoelastic components, cell shape, volume or density. The anti-aggregating effect of PRHCL (8 x 10(-4) M) in plasma significantly (p less than 0.005) decreased with time; this temporal effect was abolished by addition of eserine (1 x 10(-4) M). High concentrations of PRHCL (8 x 10(-2) M) caused: 1) increased extent of aggregation and decreased strength of the aggregates (p less than 0.01 or better); 2) elevation of both viscoelastic components for cells in plasma or buffer; 3) a discocyte-stomatocyte shape change; 4) decreased cell density (p less than 0.001) without alteration of cell volume. Our results at low concentrations of PRHCL suggest a mechanism based on an increase of RBC negative surface potential; at the highest concentration, the effects are most likely due to altered cell shape and deformability, and to decreased RBC negative surface potential.
authors.affiliation: Department of Physiology and Biophysics, University of Southern California School of Medicine, Los Angeles 90033.
authors.forename: S O
authors.initials: SO
authors.lastname: Sowemimo-Coker
authors.forename: G
authors.initials: G
authors.lastname: Yardin
authors.forename: H J
authors.initials: HJ
authors.lastname: Meiselman
mesh_terms: D001809:Blood Viscosity / Q000187:drug effects; D004548:Elasticity; D004903:Erythrocyte Aggregation / Q000187:drug effects*; D004907:Erythrocyte Deformability / Q000187:drug effects; D004912:Erythrocytes / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D011343:Procaine / Q000494:pharmacology*; D012212:Rheology
chemical_list: D011343:Procaine