Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1989-3-24
pubmed:abstractText
The effects of an acute intravenous infusion of ammonium acetate on rat cerebral glutamate and glutamine concentrations, energy metabolism, and intracellular pH were measured in vivo with 1H and 31P nuclear magnetic resonance (NMR). The level of blood ammonia maintained by the infusion protocol used in this study (approximately 500 microM, arterial blood) did not cause significant changes in arterial PCO2, PO2, or pH. Cerebral glutamate levels fell to at least 80% of the preinfusion value, whereas glutamine concentrations increased 170% relative to the preinfusion controls. The fall in brain glutamate concentrations followed a time course similar to that of the rise of brain glutamine. There were no detectable changes in the content of phosphocreatine (PCr) or nucleoside triphosphates (NTP), within the brain regions contributing to the sensitive volume of the surface coil, during the ammonia infusion. Intracellular pH, estimated from the chemical shift of the inorganic phosphate resonance relative to the resonance of PCr in the 31P spectrum, was also unchanged during the period of hyperammonemia. 1H spectra, specifically edited to allow quantitation of the brain lactate content, indicated that lactate rose steadily during the ammonia infusion. Detectable increases in brain lactate levels were observed approximately 10 min after the start of the ammonia infusion and by 50 min of infusion had more than doubled. Spectra acquired from rats that received a control infusion of sodium acetate were not different from the spectra acquired prior to the infusion of either ammonium or sodium acetate.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-3042
pubmed:author
pubmed:issnType
Print
pubmed:volume
52
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
741-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:2563756-Acetates, pubmed-meshheading:2563756-Ammonia, pubmed-meshheading:2563756-Animals, pubmed-meshheading:2563756-Brain, pubmed-meshheading:2563756-Energy Metabolism, pubmed-meshheading:2563756-Glutamates, pubmed-meshheading:2563756-Glutamic Acid, pubmed-meshheading:2563756-Glutamine, pubmed-meshheading:2563756-Hydrogen-Ion Concentration, pubmed-meshheading:2563756-Kinetics, pubmed-meshheading:2563756-Lactates, pubmed-meshheading:2563756-Lactic Acid, pubmed-meshheading:2563756-Magnetic Resonance Spectroscopy, pubmed-meshheading:2563756-Male, pubmed-meshheading:2563756-Nucleotides, pubmed-meshheading:2563756-Phosphocreatine, pubmed-meshheading:2563756-Phosphorus, pubmed-meshheading:2563756-Protons, pubmed-meshheading:2563756-Rats, pubmed-meshheading:2563756-Rats, Inbred Strains
pubmed:year
1989
pubmed:articleTitle
Effects of acute hyperammonemia on cerebral amino acid metabolism and pHi in vivo, measured by 1H and 31P nuclear magnetic resonance.
pubmed:affiliation
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.