In vivo 31P NMR spectroscopy of energy rich phosphates in the brain of the hyperammonemic rat

• Published in: Biochemical and biophysical research communications Vol. 159; no. 2; pp. 815 - 820
• Main Authors: Friolet, R., Colombo, J.P., Lazeyras, F., Aue, W.P., Kretschmer, R., Zimmermann, A., Bachmann, C.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 15.03.1989; Elsevier
• Subjects: Ammonia - blood; Ammonia - toxicity; Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Brain - drug effects; Brain - metabolism; Energy Metabolism; Fundamental and applied biological sciences. Psychology; Intermediary metabolites. Miscellaneous; Magnetic Resonance Spectroscopy; Male; Models, Biological; Other biological molecules; Phosphates - metabolism; Phosphorus; Rats; Rats, Inbred Strains; Urease; Brain; Vertebrata; Mammalia; Hyperammonemia; Rodentia; PH; NMR spectrometry; Concentration; Phosphocreatine; Metabolism; ATP; Histochemistry
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/0006-291X(89)90067-3

Hyperammonemia is a major contributing factor to the neurological ab-normalities observed in hepatic encephalopathy and in congenital defects of ammonia detoxication. In rats variable changes in labile energy rich phosphates in the brain have been observed in hyperammonemia using biochemical methods. Using 31P-NMR spectroscopy however no significant changes of the relative concentrations of the energy rich phosphates α, β and γ-ATP, phosphocreatine, inorganic phosphate and the pH were found in the fronto parietal cortex of the urease treated hyperammonemic rat. Alterations in the metabolites of these compounds do not appear to be a major pathomechanism of ammonia toxicity in this brain area.