title: Model analysis of local oxygen delivery with liposome-encapsulated hemoglobin.
abstract: Liposome-encapsulated hemoglobins (LHs) are comparable to red blood cells (RBCs) in terms of oxygen (O(2))-carrying capacity. The smaller particle size of LHs than of platelets allows their homogeneous dispersion in circulating plasma. In this study, we evaluated the effect of LH transfusion on arterial O(2) delivery through vascular trees by simulation. A mathematical model was established on the basis of the coronary arterial anatomy, the conservation of flow and RBC flux, and Poiseuille's law. The Fåhraeus-Lindqvist, Fåhraeus, and phase separation effects were considered in the model. By assuming steady perfusion, the arterial flow and O(2) delivery were calculated for five model trees undergoing the isovolumic replacement of RBCs (0.3 mg hemoglobin (Hb)/mL) with LHs (0.2 mg Hb/mL) or a plasma volume expander (PVE). The RBC-LH exchange increased both the total flow and the total O(2) flux but had almost no effect on the relative distribution of O(2) flux. In contrast, the RBC-PVE exchange decreased the total O(2) flux and increased the proportion of regions receiving a relatively low O(2) supply. Thus, LH transfusion may compensate for an enhanced bias in RBC-associated O(2) flux under hemodilution and is expected to be beneficial for both total and local O(2) delivery.
authors.affiliation: Bioengineering Division, Osaka University, Graduate School of Engineering Science, Machikaneyama-machi 1-3, Toyonaka 560-8531, Japan. matsu@me.es.osaka-u.ac.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Mano
authors.forename: Ryohei
authors.initials: R
authors.lastname: Ueha
authors.forename: Hisashi
authors.initials: H
authors.lastname: Naito
authors.forename: Masao
authors.initials: M
authors.lastname: Tanaka
mesh_terms: D001802:Blood Substitutes / Q000008:administration & dosage / Q000494:pharmacology; D003198:Computer Simulation; D006454:Hemoglobins / Q000008:administration & dosage / Q000494:pharmacology / Q000502:physiology*; D006801:Humans; D008081:Liposomes; D008954:Models, Biological; D010100:Oxygen / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology*; D010316:Particle Size; D012039:Regional Blood Flow / Q000502:physiology
chemical_list: D001802:Blood Substitutes; D006454:Hemoglobins; D008081:Liposomes; D010100:Oxygen