Altered brain phosphocreatine and ATP regulation when mitochondrial creatine kinase is absent.
SourceJournal of Neuroscience Research, 66, 5, (2001), pp. 866--72
Article / Letter to editor
Display more detailsDisplay less details
Cell Biology (UMC)
Journal of Neuroscience Research
SubjectStudy of abnormal differentiation and transformation processes in heritable and acquired disorders with the use of cell and animal models; Bestudering van abnormale differentiatie en transformatieprocessen bij erfelijke of verworven aandoeningen m.b.v. cel- en diermodellen
In cerebral gray matter, ATP concentration is closely maintained despite rapid, large increases in turnover and low substrate reserves. As seen in vivo by (31)P nuclear magnetic resonance (NMR) spectroscopy, brain ATP is stable early in seizures, a state of high energy demand, and in mild hypoxia, a state of substrate deficiency. Like other tissues with high and variable ATP turnover, cerebral gray matter has high phosphocreatine (PCr) concentration and both cytosolic and mitochondrial creatine kinase (UbMi-CK) isoenzymes. To understand the physiology of brain creatine kinases, we used (31)P NMR to study PCr and ATP regulation during seizures and hypoxia in mice with targeted deletion of the UbMi-CK gene. The baseline CK reaction rate constant (k) was higher in mutants than wild-types. During seizures, PCr and ATP decreased in mutants but not in wild-types. The k-value for the CK catalyzed reaction rate increased in wild-types but not in the mutants. Hypoxic mutants and wild-types showed similar PCr losses and stable ATP. During recovery from hypoxia, brain PCr and ATP concentrations returned to baseline in wild-types but were 20% higher than baseline in the mutants. We propose that UbMi-CK couples ATP turnover to the CK catalyzed reaction rate and regulates ATP concentration when synthesis is increased.
Upload full text
Use your RU credentials (u/z-number and password) to log in with SURFconext to upload a file for processing by the repository team.