J Physiol Society Membership
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Physiol Volume 578, Number 2, 595-603, January 15, 2007 DOI: 10.1113/jphysiol.2006.116061
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Erratum (v586,p5835)
Right arrow All Versions of this Article:
578/2/595    most recent
jphysiol.2006.116061v1
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Lin, P.-C.
Right arrow Articles by Jue, T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lin, P.-C.
Right arrow Articles by Jue, T.
Related Collections
Right arrow Integrative

INTEGRATIVE

Myoglobin translational diffusion in rat myocardium and its implication on intracellular oxygen transport

Ping-Chang Lin1, Ulrike Kreutzer1 and Thomas Jue1

1 Department of Biochemistry and Molecular Medicine, University of California Davis, Davis, CA 95616-8635, USA

Current theory of respiratory control invokes a role of myoglobin (Mb)-facilitated O2 diffusion in regulating the intracellular O2 flux, provided Mb diffusion can compete effectively with free O2 diffusion. Pulsed-field gradient NMR methods have now followed gradient-dependent changes in the distinct 1H NMR {gamma} CH3 Val E11 signal of MbO2 in perfused rat myocardium to obtain the endogenous Mb translational diffusion coefficient (DMb) of 4.24 x 10–7 cm2 s–1 at 22°C. The DMb matches precisely the value predicted by in vivo NMR rotational diffusion measurements of Mb and shows no orientation preference. Given values in the literature for the Krogh's free O2 diffusion coefficient (K0), myocardial Mb concentration and a partial pressure of O2 that half saturates Mb (P50), the analysis yields an equipoise diffusion PO2 of 1.77 mmHg, where Mb and free O2 contribute equally to the O2 flux. In the myocardium, Mb-facilitated O2 diffusion contributes increasingly more than free O2 diffusion when the PO2 falls below 1.77 mmHg. In skeletal muscle, the PO2 must fall below 5.72 mmHg. Altering the Mb P50 induces modest change. Mb-facilitated diffusion has a higher poise in skeletal muscle than in myocardium. Because the basal PO2 hovers around 10 mmHg, Mb does not have a predominant role in facilitating O2 transport in myocardium but contributes significantly only when cellular oxygen falls below the equipoise diffusion PO2.

(Received 26 June 2006; accepted after revision 5 October 2006; first published online 12 October 2006)
Corresponding author T. Jue: Department of Biochemistry and Molecular Medicine, University of California Davis, Davis, CA 95616-8635, USA. Email: tjue{at}ucdavis.edu




This article has been cited by other articles:


Home page
 J. Physiol.Home page
Corrigendum
J. Physiol., December 1, 2008; 586(23): 5835 - 5835.
[Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
P. J. Ponganis, U. Kreutzer, T. K. Stockard, P.-C. Lin, N. Sailasuta, T.-K. Tran, R. Hurd, and T. Jue
Blood flow and metabolic regulation in seal muscle during apnea
J. Exp. Biol., October 15, 2008; 211(20): 3323 - 3332.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
J. B. Wittenberg and B. A. Wittenberg
Myoglobin-enhanced oxygen delivery to isolated cardiac mitochondria
J. Exp. Biol., June 15, 2007; 210(12): 2082 - 2090.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
P.-C. Lin, U. Kreutzer, and T. Jue
Anisotropy and Temperature Dependence of Myoglobin Translational Diffusion in Myocardium: Implication for Oxygen Transport and Cellular Architecture
Biophys. J., April 1, 2007; 92(7): 2608 - 2620.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2007 The Physiological Society.