31P NMR studies of human soleus and gastrocnemius show differences in the J gamma beta coupling constant of ATP and in intracellular free magnesium.
MAGMA
; 4(1): 47-53, 1996 Mar.
Article
em En
| MEDLINE
| ID: mdl-8774001
Localized proton decoupled 31P in vivo NMR spectroscopy of the human calf muscle was performed using a 1.5-T whole-body imager and the slice selective two-dimensional chemical-shift-imaging (2D-CSI) technique. The 31P-31P coupling constants and the chemical shifts of ATP were compared in gastrocnemius and soleus. Significant differences were found in the coupling constant J gamma beta: (18.1 +/- 0.7) Hz versus (17.1 +/- 0.6) Hz (means +/- SD, P < 10-5). Differences were also observed in the chemical shift separation delta alpha beta between the alpha- and beta-ATP signal: (8.498 +/- 0.023) ppm versus (8.522 +/- 0.222) ppm (p < 0.001) in gastrocnemius and soleus, respectively. A higher [MgATP]/[ATPfree] ratio and a significantly higher level of intracellular free magnesium of (0.52 +/- 0.06) mM in gastrocnemius versus (0.46 +/- 0.05) mM in soleus (p < 0.001) can be derived based on delta alpha beta and KDMgATP. Heterogeneity needs to be taken into account in clinical studies on magnesium by NMR methods in calf muscle. The coupling constant J gamma beta provides additional information, possibly on enzymatic processes, and correlates with [Mg2+free]. The detailed analysis of muscles with different fiber type characteristics lends support to the significance of this parameter in evaluating metabolism. The data reported can be used as prior knowledge for fits in which the coupling constants are set to a fixed value.
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Base de dados:
MEDLINE
Assunto principal:
Espectroscopia de Ressonância Magnética
/
Trifosfato de Adenosina
/
Músculo Esquelético
/
Magnésio
Limite:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
MAGMA
Assunto da revista:
DIAGNOSTICO POR IMAGEM
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Alemanha