Modular 31 P wideband inversion transfer for integrative analysis of adenosine triphosphate metabolism, T1 relaxation and molecular dynamics in skeletal muscle at 7T.
Magn Reson Med
; 81(6): 3440-3452, 2019 06.
Article
in En
| MEDLINE
| ID: mdl-30793793
ABSTRACT
PURPOSE:
For efficient and integrative analysis of de novo adenosine triphosphate (ATP) synthesis, creatine-kinase-mediated ATP synthesis, T1 relaxation time, and ATP molecular motion dynamics in human skeletal muscle at rest.METHODS:
Four inversion-transfer modules differing in center inversion frequency were combined to generate amplified magnetization transfer (MT) effects in targeted MT pathways, including Pi â γ-ATP, PCr â γ-ATP, and 31 Pγ(α)ATP â 31 PßATP . MT effects from both forward and reverse exchange kinetic pathways were acquired to reduce potential bias and confounding factors in integrated data analysis.RESULTS:
Kinetic data collected using 4 wideband inversion modules (8 minutes each) yielded the forward exchange rate constants, kPCrâγATP = 0.31 ± 0.05 s-1 and kPiâγATP = 0.064 ± 0.012 s-1 , and the reverse exchange rate constants, kγATPâPi = 0.034 ± 0.006 s-1 and kγATPâPCr = 1.37 ± 0.22 s-1 , respectively. The cross-relaxation rate constant, σγ(α) â ßATP was -0.20 ± 0.03 s-1 , corresponding to ATP rotational correlation time τc of 0.8 ± 0.1 × 10-7 seconds. The intrinsic T1 relaxation times were Pi (9.2 ± 1.4 seconds), PCr (6.2 ± 0.4 seconds), γ-ATP (1.8 ± 0.1 seconds), α-ATP (1.4 ± 0.1 seconds), and ß-ATP (1.1 ± 0.1 seconds). Muscle ATP T1 values were found to be significantly longer than those previously measured in the brain using a similar method.CONCLUSION:
A combination of multiple inversion transfer modules provides a comprehensive and integrated analysis of ATP metabolism and molecular motion dynamics. This relatively fast technique could be potentially useful for studying metabolic disorders in skeletal muscle.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Phosphorus Isotopes
/
Brain
/
Magnetic Resonance Imaging
/
Adenosine Triphosphate
/
Muscle, Skeletal
Limits:
Adult
/
Female
/
Humans
/
Male
Language:
En
Journal:
Magn Reson Med
Year:
2019
Document type:
Article