Brain creatine phosphate and creatine kinase in mice fed an analogue of creatine. Academic Article uri icon

Overview

abstract

  • Brain phosphocreatine (PCr) concentration and creatine kinase (CK) activity have been studied by 31P nuclear magnetic resonance (NMR) spectroscopy in mice fed an analogue of creatine, beta-guanidinopropionic acid (GPA). The phosphorylated analogue (GPAP), which almost completely replaces PCr in skeletal muscle, is a poor substrate for CK. Mice, which received GPA in food (2%) and water (0.5%) for up to 9 months beginning at 35 days of age, were normal in appearance and activity. Maximal brain GPAP concentration, reached after two weeks of feedings, was approximately equal to the concentration of PCr. The concentration of PCr decreased at least 20% relative to that of the nucleoside triphosphates. When GPA feedings were stopped, GPAP disappeared in about 20 days from skeletal muscle, but only after 40-50 days from brain. Steady-state NMR saturation transfer studies showed a markedly reduced chemical exchange rate from PCr to ATP in brains of GPA-fed mice. These results suggest a compartmentation of brain PCr. The GPA-accessible PCr compartment has a slow rate of PCr turnover compared to skeletal muscle. The slow reaction rate of the GPA-inaccessible PCr as a CK substrate is consistent with the hypothesis that this residual PCr is the same compartment which is stable in hypoxic or seizing animals.

publication date

  • March 27, 1989

Research

keywords

  • Brain
  • Creatine Kinase
  • Diet
  • Guanidines
  • Phosphocreatine
  • Propionates

Identity

Scopus Document Identifier

  • 0024559194

Digital Object Identifier (DOI)

  • 10.1016/0006-8993(89)90035-8

PubMed ID

  • 2706511

Additional Document Info

volume

  • 483

issue

  • 1