Spatial distribution of deoxymyoglobin in human muscle: an index of local tissue oxygenation.

The proximal histidyl NdeltaH signal of myoglobin is detectable in 1H NMR spectra of myocardial and skeletal muscle, and its intensity reflects the intracellular oxygenation. At 1.5 Tesla (T), the typical field strength of clinical magnetic resonance imaging (MRI) magnets, the paramagnetic relaxation contribution decreases sufficiently to permit the implementation of chemical shift imaging technique to map the spatial distribution of the deoxy Mb NdeltaH signal from human gastrocnemius muscle.

Metabolic response in Arenicola marina to limiting oxygen as reflected in the 1H-NMR oxymyoglobin signal.

Many intertidal animals can endure prolonged periods of environmental stress and have developed strategies to preserve a functioning energy state in the cell. Recent 1H/31P-NMR techniques have allowed investigators to monitor directly mammalian tissue metabolism in vivo. In particular, the signals of myoglobin (Mb) offer a unique opportunity to explore the intracellular oxygen-partial-pressure [p(O2)] interaction in Arenicola marina, a standard model to study hypoxia tolerance in invertebrates.

Two-dimensional NMR characterization of the deoxymyoglobin heme pocket.

Traditionally, assigning the heme protein resonances has relied heavily on the comparison of spectra arising from protein reconstituted with specifically deuterated hemes and the native form. Such an approach can identify tentatively the broad, overlapping signals in the Fe(II) high-spin heme protein spectra. Although 2D NMR studies have reported alternative approaches to detect and assign paramagnetic signals, their effectiveness is limited primarily to Fe(III) low-spin systems and still depends upon isotopic labeling results to be definitive.

Myoglobin signal as an NMR tissue thermometer: implication for hyperthermia treatment of tumors.

Measuring local tissue temperature is critical in establishing a rational approach for hyperthermia treatment of tumors. We have found that the heme signals of myoglobin provide a unique basis for NMR thermometry in vivo. In particular the 5-methyl heme signal of MbCN exhibits a sharp, temperature-dependent resonance that is distinguishable in the tissue spectrum.

1H NMR approach to observe tissue oxygenation with the signals of myoglobin.

The myoglobin technique measures oxygen tension in myocytes. It relies on a quantitative measurement of the Val E11 and His F8 signals and an accurate value for the [O2]50 for Mb. Even though the Mb oxygen affinity in the cell is in question, the NMR results still reflect the degree of Mb oxygen saturation.