HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 288/6/H2897    most recent 01184.2004v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (13) Citing Articles via Google Scholar Google Scholar Articles by Sakai, H. Articles by Intaglietta, M. Search for Related Content PubMed PubMed Citation Articles by Sakai, H. Articles by Intaglietta, M.

Oxygen release from low and normal P₅₀ Hb vesicles in transiently occluded arterioles of the hamster window model

¹Advanced Research Institute for Science and Engineering, Waseda University, Tokyo, Japan; and ²Department of Bioengineering, University of California-San Diego, and ³La Jolla Bioengineering Institute, La Jolla, California

Submitted 27 November 2004 ; accepted in final form 24 January 2005

A phospholipid vesicle encapsulating Hb [Hb vesicle (HbV)] has been developed as a transfusion alternative. One characteristic of HbV is that the O₂ affinity [PO₂ at which Hb is 50% saturated (P₅₀)] of Hb can be easily regulated by the amount of the coencapsulated allosteric effector pyridoxal 5'-phosphate. In this study, we prepared two HbVs with different P₅₀s (8 and 29 mmHg, termed HbV₈ and HbV₂₉, respectively) and observed their O₂-releasing behavior from an occluded arteriole in a hamster skinfold window model. Conscious hamsters received HbV₈ or HbV₂₉ at a dose rate of 7 ml/kg. In the microscopic view, an arteriole (diameter: 53.0 ± 6.6 µm) was occluded transcutaneously by a glass pipette on a manipulator, and the reduction of the intra-arteriolar PO₂ 100 µm down from the occlusion was measured by the phosphorescence quenching of preinfused Pd-porphyrin. The baseline arteriolar PO₂ (50–52 mmHg) decreased to about 5 mmHg for all the groups. Occlusion after HbV₈ infusion showed a slightly slower rate of PO₂ reduction compared with that after HbV₂₉ infusion. The arteriolar O₂ content was calculated at each reducing PO₂ in combination with the O₂ equilibrium curves of HbVs, and it was clarified that HbV₈ showed a significantly slower rate of O₂ release compared with HbV₂₉ and was a primary source of O₂ (maximum fraction, 0.55) overwhelming red blood cells when the PO₂ was reduced (e.g., <10 mmHg) despite a small dosage of HbV. This result supports the possible utilization of Hb-based O₂ carriers with lower P₅₀ for oxygenation of ischemic tissues.

blood substitutes; artificial red blood cells; occlusion; microhemodynamics; liposome

This article has been cited by other articles:

				P. Cabrales, A. G. Tsai, P. C. Johnson, and M. Intaglietta Oxygen release from arterioles with normal flow and no-flow conditions J Appl Physiol, May 1, 2006; 100(5): 1569 - 1576. [Abstract] [Full Text] [PDF]

				J. A. Plock, C. Contaldo, H. Sakai, E. Tsuchida, M. Leunig, A. Banic, M. D. Menger, and D. Erni Is hemoglobin in hemoglobin vesicles infused for isovolemic hemodilution necessary to improve oxygenation in critically ischemic hamster skin? Am J Physiol Heart Circ Physiol, December 1, 2005; 289(6): H2624 - H2631. [Abstract] [Full Text] [PDF]