Increase of creatine kinase activity in the visual cortex of human brain during visual stimulation: a 31P magnetization transfer study.
31P magnetic resonance spectroscopy was used to investigate changes in high energy phosphate levels and creatine kinase (CK) kinetics induced in the human visual cortex during photic stimulation. CK kinetics was evaluated by measuring the apparent unidirectional rate constant (kf) in the "forward" direction (i.e., in the direction of ATP synthesis from phosphocreatine). kf increased 34% in the visual cortex areas during stimulation without significant changes of steady-state concentration of high energy phosphate compounds, indicating that CK turnover is elevated during increased neuronal activity.
Chen
W
W
Center for Magnetic Resonance Research, Radiology Department, University of Minnesota, School of Medicine, Minneapolis 55455, USA.
Zhu
X H
XH
Adriany
G
G
Ugurbil
K
K
D000255:Adenosine Triphosphate / Q000378:metabolism; D003402:Creatine Kinase / Q000378:metabolism*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008280:Magnetics; D010758:Phosphorus / Q000378:metabolism*; D010759:Phosphorus Isotopes; D010775:Photic Stimulation; D012815:Signal Processing, Computer-Assisted; D014793:Visual Cortex / Q000201:enzymology*
D010759:Phosphorus Isotopes; D010758:Phosphorus; D000255:Adenosine Triphosphate; D003402:Creatine Kinase