title: Effects of choline on hemorheological properties and NO metabolism of human erythrocytes.
abstract: OBJECTIVE
  To determine the effects of choline on red blood cell membrane properties and NO metabolism.
  
  
  METHODS
  Aliquots of venous blood from eleven healthy subjects were incubated in vitro with choline concentrations 10(-10) to 10(-3) M. The following parameters were determined: erythrocyte deformability, aggregation and membrane lipid fluidity, plasma K+, Na+, Ca2+, total blood haemoglobin and methemoglobin concentrations. Additionally, plasma and intra-erythrocyte nitrites concentrations were measured.
  
  
  RESULTS
  Choline increases erythrocyte deformability at lower shear stresses, decreases erythrocyte aggregation, increases membrane lipid fluidity, and decreases of Na+ plasma concentrations. We also find an increase of nitrites concentration both in the plasma and in the intra-erythrocyte compartment.
  
  
  CONCLUSIONS
  Choline induces changes on erythrocyte membrane properties, Na+ plasma concentration, and NO metabolites concentrations.
authors.affiliation: Institute of Biochemistry, Faculty of Medicine, University of Lisbon, Avenida Prof. Egas Moniz, 1649-028 Lisbon, Portugal.
authors.forename: Tiago
authors.initials: T
authors.lastname: Santos
authors.forename: Rui
authors.initials: R
authors.lastname: Mesquita
authors.forename: João
authors.initials: J
authors.lastname: Martins E Silva
authors.forename: Carlota
authors.initials: C
authors.lastname: Saldanha
mesh_terms: D000328:Adult; D002118:Calcium / Q000097:blood; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002794:Choline / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000187:drug effects* / Q000378:metabolism; D006454:Hemoglobins / Q000096:biosynthesis; D018056:Hemorheology / Q000187:drug effects*; D006801:Humans; D050356:Lipid Metabolism; D008082:Lipotropic Agents / Q000494:pharmacology; D008297:Male; D008563:Membrane Lipids / Q000737:chemistry; D008706:Methemoglobin / Q000096:biosynthesis; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism; D011188:Potassium / Q000097:blood; D012964:Sodium / Q000097:blood
chemical_list: D006454:Hemoglobins; D008082:Lipotropic Agents; D008563:Membrane Lipids; D009573:Nitrites; D009569:Nitric Oxide; D008706:Methemoglobin; D012964:Sodium; D002794:Choline; D011188:Potassium; D002118:Calcium