31P magnetization transfer studies in the monkey brain.
The forward and reverse rates through the creatine-kinase (CK) catalyzed reaction, phosphocreatine + ADP+ H+ kf in equilibrium with kr creatine + ATP in the in vivo monkey brain were measured using the techniques of saturation transfer (ST) and inversion transfer (IT) 31P nuclear magnetic resonance (NMR) spectroscopy. Independent checks on the ST apparent longitudinal relaxation (tau) data could be obtained from the parameters determined from the IT analyses. At near-equilibrium it is assumed that the forward-to-reverse flux ratio lies close to 1.0. In the monkey brain the value for the forward-to-reverse flux ratio obtained is 1.37 +/- 0.26 calculated from ST with average tau values from IT initial slopes, a value which is not significantly different from unity. The present NMR data point to the CK reaction in the living monkey brain being maintained at or near equilibrium.
Mora
B N
BN
Magnetic Resonance Spectroscopy Laboratory, Huntington Medical Research Institutes, Pasadena, California 91105.
Narasimhan
P T
PT
Ross
B D
BD
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism*; D003402:Creatine Kinase / Q000378:metabolism; D005260:Female; D008252:Macaca fascicularis; D009682:Magnetic Resonance Spectroscopy; D010725:Phosphocreatine / Q000378:metabolism
D010725:Phosphocreatine; D000255:Adenosine Triphosphate; D003402:Creatine Kinase