Abstract
The 1H nuclear magnetic resonance (NMR) signal of tissue myoglobin has provided an opportunity to determine the critical O2 level in saline- perfused myocardium at room temperature. Above the intracellular PO2 of 4 mmHg, the myocardium exhibits no sign of hypoxia. At 4 mmHg, the rate pressure product (RPP) decreases, and the lactate formation rate, measured enzymatically, increases. However, O2 consumption and the 31P-NMR signal of phosphocreatine level remain relatively constant until the cellular PO2 reaches 2 mmHg. The ATP signal intensity dips only when cellular O2 reaches 0.8 mmHg, while pH remains unchanged at 7.2. The sequential nature of the cellular response to limiting O2, starting with alterations in the lactate formation rate and RPP, indicates that NADH, rather than ADP, signals tissue hypoxia. Moreover, the study suggests that the O2 gradient from capillary to cell is larger than that from cytosol to mitochondria.
| Original language | English (US) |
|---|---|
| Journal | American Journal of Physiology - Heart and Circulatory Physiology |
| Volume | 268 |
| Issue number | 4 37-4 |
| State | Published - 1995 |
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Keywords
- bioenergetics
- heart
- oxidative phosphorylation
ASJC Scopus subject areas
- Physiology
- Medicine(all)
Cite this
Critical intracellular O2 in myocardium as determined by 1H nuclear magnetic resonance signal of myoglobin. / Kreutzer, U.; Jue, Thomas.
In: American Journal of Physiology - Heart and Circulatory Physiology, Vol. 268, No. 4 37-4, 1995.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Critical intracellular O2 in myocardium as determined by 1H nuclear magnetic resonance signal of myoglobin
AU - Kreutzer, U.
AU - Jue, Thomas
PY - 1995
Y1 - 1995
N2 - The 1H nuclear magnetic resonance (NMR) signal of tissue myoglobin has provided an opportunity to determine the critical O2 level in saline- perfused myocardium at room temperature. Above the intracellular PO2 of 4 mmHg, the myocardium exhibits no sign of hypoxia. At 4 mmHg, the rate pressure product (RPP) decreases, and the lactate formation rate, measured enzymatically, increases. However, O2 consumption and the 31P-NMR signal of phosphocreatine level remain relatively constant until the cellular PO2 reaches 2 mmHg. The ATP signal intensity dips only when cellular O2 reaches 0.8 mmHg, while pH remains unchanged at 7.2. The sequential nature of the cellular response to limiting O2, starting with alterations in the lactate formation rate and RPP, indicates that NADH, rather than ADP, signals tissue hypoxia. Moreover, the study suggests that the O2 gradient from capillary to cell is larger than that from cytosol to mitochondria.
AB - The 1H nuclear magnetic resonance (NMR) signal of tissue myoglobin has provided an opportunity to determine the critical O2 level in saline- perfused myocardium at room temperature. Above the intracellular PO2 of 4 mmHg, the myocardium exhibits no sign of hypoxia. At 4 mmHg, the rate pressure product (RPP) decreases, and the lactate formation rate, measured enzymatically, increases. However, O2 consumption and the 31P-NMR signal of phosphocreatine level remain relatively constant until the cellular PO2 reaches 2 mmHg. The ATP signal intensity dips only when cellular O2 reaches 0.8 mmHg, while pH remains unchanged at 7.2. The sequential nature of the cellular response to limiting O2, starting with alterations in the lactate formation rate and RPP, indicates that NADH, rather than ADP, signals tissue hypoxia. Moreover, the study suggests that the O2 gradient from capillary to cell is larger than that from cytosol to mitochondria.
KW - bioenergetics
KW - heart
KW - oxidative phosphorylation
UR - http://www.scopus.com/inward/record.url?scp=0028901573&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028901573&partnerID=8YFLogxK
M3 - Article
C2 - 7733370
AN - SCOPUS:0028901573
VL - 268
JO - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
JF - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
SN - 1931-857X
IS - 4 37-4
ER -