title: Erythrocyte consumption of nitric oxide: competition experiment and model analysis.
abstract: It is generally believed that the erythrocyte membrane is highly permeable to nitric oxide (NO). To prevent NO from freely entering and being scavenged by the red blood cell (RBC), it has been suggested that NO consumption is limited by the mass transfer resistance of the diffusion layer adjacent to the erythrocyte membrane. Recently, we (Vaughn et al. (2000). J. Biol. Chem. 275, 2342) presented an experimental technique that overcomes experimental diffusional limitations and showed that RBCs also possess a mechanism to slow nitric oxide uptake. Here, we present a mathematical analysis of this technique by modeling the NO uptake of a single cell. We obtain additional data (n = 33, total) by use of the competition experiment and, through application of the model, show that either the RBC membrane permeability to NO or the intracellular reaction rate between NO and hemoglobin (Hb) is at least 2000-fold lower than previously thought. As a result, RBCs react with NO at a rate three orders of magnitude slower than free oxyHb. This phenomena may play an important role in NO bioavailability.
authors.affiliation: Department of Chemical Engineering, University of California, Los Angeles, California 90095, USA.
authors.forename: M W
authors.initials: MW
authors.lastname: Vaughn
authors.forename: K T
authors.initials: KT
authors.lastname: Huang
authors.forename: L
authors.initials: L
authors.lastname: Kuo
authors.forename: J C
authors.initials: JC
authors.lastname: Liao
mesh_terms: D000818:Animals; D002417:Cattle; D002463:Cell Membrane Permeability; D003198:Computer Simulation; D004058:Diffusion; D004910:Erythrocyte Membrane / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism*; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism; D007700:Kinetics; D008954:Models, Biological; D009010:Monte Carlo Method; D009569:Nitric Oxide / Q000097:blood*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009589:Nitrogen Oxides; D010108:Oxyhemoglobins / Q000378:metabolism; D013096:Spermine / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D006454:Hemoglobins; D020030:Nitric Oxide Donors; D009589:Nitrogen Oxides; D010108:Oxyhemoglobins; C091861:spermine nitric oxide complex; D013096:Spermine; D009569:Nitric Oxide