31P nuclear magnetic relaxation studies of phosphocreatine in intact muscle: determination of intracellular free magnesium.
AUTOR(ES)
Cohen, S M
RESUMO
31P nuclear magnetic relaxation rates for phosphocreatine in intact frog gastrocnemius were compared with those observed in model solutions at 4 degrees, a temperature at which muscle maintains its physiological state for at least 5 hr. Both nuclear Overhauser effect and spin-lattice relaxation rate (1/T1) experiments indicate that dipole-dipole interactions from the dominant relaxation path for 31P in intact muscle and model solutions, independent of phosphocreatine and Mg concentrations. Spin-spin relaxation rates (1/T2) measured by modified Carr-Purcell-Melboom-Gill spin-echo experiments suggest the importance of scalar coupling modulated by chemical exchange with free Mg. From these results, we estimate the free intracellular Mg in intact muscle as 4.4 mM and demonstrate that 31P T2 experiments can be used as a tool for studying free Mg levels with minimum disturbance of the intact cell.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=431921Documentos Relacionados
- High resolution 31P nuclear magnetic resonance studies of intact yeast cells.
- 31P nuclear magnetic resonance studies of glycogen phosphorylase from rabbit skeletal muscle: ionization states of pyridoxal 5'-phosphate.
- Mitochondrial regulation of phosphocreatine/inorganic phosphate ratios in exercising human muscle: a gated 31P NMR study.
- 31P nuclear magnetic resonance studies of HeLa cells
- 31P nuclear magnetic resonance studies of Ehrlich ascites tumor cells.
