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

Ping-Chang Lin, Ulrike Kreutzer, Thomas Jue

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

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 γ CH3 Val E11 signal of MbO2 in perfused rat myocardium to obtain the endogenous Mb translational diffusion coefficient (DMb) of 4.24 × 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.

Original languageEnglish (US)
Pages (from-to)595-603
Number of pages9
JournalJournal of Physiology
Volume578
Issue number2
DOIs
StatePublished - Jan 15 2007

Fingerprint

Myoglobin
Myocardium
Oxygen
Facilitated Diffusion
Skeletal Muscle
Partial Pressure

ASJC Scopus subject areas

  • Physiology

Cite this

Myoglobin translational diffusion in rat myocardium and its implication on intracellular oxygen transport. / Lin, Ping-Chang; Kreutzer, Ulrike; Jue, Thomas.

In: Journal of Physiology, Vol. 578, No. 2, 15.01.2007, p. 595-603.

Research output: Contribution to journalArticle

Lin, Ping-Chang ; Kreutzer, Ulrike ; Jue, Thomas. / Myoglobin translational diffusion in rat myocardium and its implication on intracellular oxygen transport. In: Journal of Physiology. 2007 ; Vol. 578, No. 2. pp. 595-603.
@article{e72e0f4546594df09deb310980811fb0,
title = "Myoglobin translational diffusion in rat myocardium and its implication on intracellular oxygen transport",
abstract = "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 γ CH3 Val E11 signal of MbO2 in perfused rat myocardium to obtain the endogenous Mb translational diffusion coefficient (DMb) of 4.24 × 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.",
author = "Ping-Chang Lin and Ulrike Kreutzer and Thomas Jue",
year = "2007",
month = "1",
day = "15",
doi = "10.1113/jphysiol.2006.116061",
language = "English (US)",
volume = "578",
pages = "595--603",
journal = "Journal of Physiology",
issn = "0022-3751",
publisher = "Wiley-Blackwell",
number = "2",

}

TY - JOUR

T1 - Myoglobin translational diffusion in rat myocardium and its implication on intracellular oxygen transport

AU - Lin, Ping-Chang

AU - Kreutzer, Ulrike

AU - Jue, Thomas

PY - 2007/1/15

Y1 - 2007/1/15

N2 - 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 γ CH3 Val E11 signal of MbO2 in perfused rat myocardium to obtain the endogenous Mb translational diffusion coefficient (DMb) of 4.24 × 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.

AB - 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 γ CH3 Val E11 signal of MbO2 in perfused rat myocardium to obtain the endogenous Mb translational diffusion coefficient (DMb) of 4.24 × 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.

UR - http://www.scopus.com/inward/record.url?scp=33846194186&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33846194186&partnerID=8YFLogxK

U2 - 10.1113/jphysiol.2006.116061

DO - 10.1113/jphysiol.2006.116061

M3 - Article

C2 - 17038435

AN - SCOPUS:33846194186

VL - 578

SP - 595

EP - 603

JO - Journal of Physiology

JF - Journal of Physiology

SN - 0022-3751

IS - 2

ER -