scholarly journals In vivo 31P-NMR spectroscopy at epicardium under hypoxia.

1989 ◽  
Vol 53 (9) ◽  
pp. 1098-1099 ◽  
Author(s):  
HIROAKI ARISAKA ◽  
TERUHIKO TOYAOKA ◽  
SAICHI HOSODA
Keyword(s):  
Nmr Spectroscopy ◽  
31P Nmr ◽  
31P Nmr Spectroscopy

31P-NMR spectroscopy of isolated perfused rat lung

1993 ◽  
Vol 74 (4) ◽  
pp. 1549-1554 ◽  
Author(s):  
Y. Hayashi ◽  
T. Inubushi ◽  
S. Nioka ◽  
R. E. Forster
Keyword(s):  
Nmr Spectroscopy ◽  
Intracellular Ph ◽  
31P Nmr ◽  
Peak Height ◽  
31P Nmr Spectroscopy ◽  
Line Broadening ◽  
Membrane Phospholipids ◽  
The Difference ◽  
Inflated Lung

We obtained 202.5-MHz 31P-nuclear magnetic resonance (NMR) spectra of isolated perfused rat lungs, degassed and inflated, and of lung extract. The spectra included those of ATP, ADP, phosphocreatine (PCr), inorganic phosphate (Pi), phosphomonoesters, phosphodiesters, and a broad component due to the membrane phospholipids. The line width at one-half peak height for beta-ATP was 1.0 ppm for the degassed lung and 1.2 ppm for the inflated lung. This suggests that the air-water interfaces in inflated lung, which produce proton NMR line broadening, do not act prominently in 31P-NMR spectroscopy. In a degassed lung, when perfusion was stopped for up to 30 min, PCr and ATP peaks decreased progressively with time while Pi and phosphomonoester peaks increased. On return of flow, these changes reversed. The intracellular pH values calculated from the difference in magnetic field between PCr and Pi peaks of inflated and degassed lungs were 7.16 +/- 0.10 (SD; n = 4) and 6.99 +/- 0.10 (n = 4), respectively. The change of intracellular pH caused by 30 min of ischemia was -0.2 pH units. Our findings indicate that air-water interfaces should not broaden lung 31P peaks in vivo.

31P NMR spectroscopy of in vivo tumors

1984 ◽  
Vol 2 (1) ◽  
pp. 70-71
Author(s):  
T.C. Ng ◽  
W.T. Evanochko ◽  
R.N. Hiramoto ◽  
V.K. Ghanta ◽  
M.B. Lilly ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
31P Nmr ◽  
31P Nmr Spectroscopy

Partial cerebral ischemia assessed by “in vivo” 31P NMR spectroscopy in rats

1992 ◽  
Vol 10 (5) ◽  
pp. 769-772 ◽  
Author(s):  
M.A. Macrì ◽  
R. Campanella ◽  
G. Garreffa ◽  
M. Occhigrossi ◽  
F. De Luca ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Nmr Spectroscopy ◽  
31P Nmr ◽  
31P Nmr Spectroscopy

scholarly journals Localized 31P NMR spectroscopy of the amt human brain in vivo using stimulated-echo (STEAM) sequences

1990 ◽  
Vol 89 (2) ◽  
pp. 343-361 ◽  
Author(s):  
K.D Merboldt ◽  
D Chien ◽  
W Hänicke ◽  
M.L Gyngell ◽  
H Bruhn ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Human Brain ◽  
31P Nmr ◽  
31P Nmr Spectroscopy ◽  
Stimulated Echo

scholarly journals Impact of Inhibition of the Mitochondrial Pyruvate Carrier on the Tumor Extracellular pH as Measured by CEST-MRI

Cancers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 4278
Author(s):  
Chloé Buyse ◽  
Nicolas Joudiou ◽  
Cyril Corbet ◽  
Olivier Feron ◽  
Lionel Mignion ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
31P Nmr ◽  
Glucose Consumption ◽  
Extracellular Ph ◽  
31P Nmr Spectroscopy ◽  
Parametric Images ◽  
Mitochondrial Pyruvate Carrier ◽  
Cest Mri ◽  
The Impact

(1) Background: The acidosis of the tumor micro-environment may have profound impact on cancer progression and on the efficacy of treatments. In the present study, we evaluated the impact of a treatment with UK-5099, a mitochondrial pyruvate carrier (MPC) inhibitor on tumor extracellular pH (pHe); (2) Methods: glucose consumption, lactate secretion and extracellular acidification rate (ECAR) were measured in vitro after exposure of cervix cancer SiHa cells and breast cancer 4T1 cells to UK-5099 (10 µM). Mice bearing the 4T1 tumor model were treated daily during four days with UK-5099 (3 mg/kg). The pHe was evaluated in vivo using either chemical exchange saturation transfer (CEST)-MRI with iopamidol as pHe reporter probe or 31P-NMR spectroscopy with 3-aminopropylphosphonate (3-APP). MR protocols were applied before and after 4 days of treatment; (3) Results: glucose consumption, lactate release and ECAR were increased in both cell lines after UK-5099 exposure. CEST-MRI showed a significant decrease in tumor pHe of 0.22 units in UK-5099-treated mice while there was no change over time for mice treated with the vehicle. Parametric images showed a large heterogeneity in response with 16% of voxels shifting to pHe values under 7.0. In contrast, 31P-NMR spectroscopy was unable to detect any significant variation in pHe; (4) Conclusions: MPC inhibition led to a moderate acidification of the extracellular medium in vivo. CEST-MRI provided high resolution parametric images (0.44 µL/voxel) of pHe highlighting the heterogeneity of response within the tumor when exposed to UK-5099.

Skeletal muscle bioenergetics during frequency-dependent fatigue

1991 ◽  
Vol 260 (3) ◽  
pp. C643-C651 ◽  
Author(s):  
C. R. Bridges ◽  
B. J. Clark ◽  
R. L. Hammond ◽  
L. W. Stephenson
Keyword(s):  
Skeletal Muscle ◽  
Nmr Spectroscopy ◽  
31P Nmr ◽  
High Energy ◽  
Metabolic Energy ◽  
31P Nmr Spectroscopy ◽  
External Work ◽  
Dynamic Contractions ◽  
High Energy Phosphate Metabolism

The bioenergetic correlates of skeletal muscle fatigue were assessed in vivo with phosphorus-31 nuclear magnetic resonance (31P-NMR) spectroscopy. After surgical construction of latissimus dorsi muscle ventricles, seven beagles underwent 31P-NMR spectroscopy during 12-min exercise protocols at 25- and 85-Hz stimulation frequencies and during both isovolumetric and dynamic contractions. Exercise at 85 Hz was associated with significantly greater fatigue than exercise at 25 Hz. At both frequencies, the onset of exercise was associated with a marked increase in inorganic phosphate (Pi) and a decrease in phosphocreatine (PCr). As the muscle fatigued at 85 Hz but not at 25 Hz, the phosphorus spectra returned to near baseline with a decrease in Pi and increase in PCr. For a given amount of force generated, the Pi-to-PCr ratio was higher for dynamic contractions than for isovolumetric contractions. This study indicates that high-frequency fatigue is unlikely to result from the direct effects of high-energy phosphate metabolism and that contractions producing external work consume more metabolic energy than equally forceful isometric contractions.

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