title: Study of radiation induced changes of phosphorus metabolism in mice by (31)P NMR spectroscopy.
abstract: BACKGROUND
  The aim of this study was to examine whether (31)P NMR can efficiently detect X-ray radiation induced changes of energy metabolism in mice. Exposure to ionizing radiation causes changes in energy supply that are associated with the tissue damage because of oxidative stress and uncoupled oxidative phosphorylation. This has as a consequence decreased phosphocreatine to adenosine triphosphate ratio (Pcr/ATP) as well as increased creatine kinase (CK) and liver enzymes (transaminases AST and ALT) levels in serum.
  
  
  METHODS
  In this study, experimental mice that received 7 Gy of X-ray radiation and a control group were studied by (31)P NMR spectroscopy and biochemically by measuring CK and liver enzyme levels in plasma. Mice (irradiated and control) were measured at regular time intervals for the next three weeks after the exposure to radiation.
  
  
  RESULTS
  A significant change in the Pcr/ATP ratio, determined from corresponding peaks of (31)P NMR spectra, was observed in the 7 Gy group 2 days or more after the irradiation, while no significant change in the Pcr/ATP ratio, was observed in the control group. This result was supported by parallel measurements of CK levels that were highly increased immediately after the irradiation which correlates with the observed decrease of the Pcr/ATP ratio and with it associated drop of muscle energy supply.
  
  
  CONCLUSIONS
  The (31)P NMR measurements of the Pcr/ATP ratio can in principle serve as an instantaneous and noninvasive index for assessment of the received dose of irradiation.
authors.affiliation: Jozef Stefan Institute, Ljubljana, Slovenia.
authors.forename: Igor
authors.initials: I
authors.lastname: Sersa
authors.forename: Simona
authors.initials: S
authors.lastname: Kranjc
authors.forename: Gregor
authors.initials: G
authors.lastname: Sersa
authors.forename: Alenka
authors.initials: A
authors.lastname: Nemec-Svete
authors.forename: Bojan
authors.initials: B
authors.lastname: Lozar
authors.forename: Ana
authors.initials: A
authors.lastname: Sepe
authors.forename: Jernej
authors.initials: J
authors.lastname: Vidmar
authors.forename: Marjeta
authors.initials: M
authors.lastname: Sentjurc