Cerebral high-energy compounds: changes in anoxia

¹ Department of Physiology, University of Kansas, Lawrence, Kansas

Acid-soluble phosphates of rat brain during anoxia were determined by ion-exchange and chemical procedures. There is a general shift during anoxia of triphosphate nucleotides to monophosphates and a very rapid breakdown of phosphoryl-creatine. However, total phosphate leaving the high-energy phosphate pool is not equal to the changes in inorganic phosphate; inorganic phosphate change is much larger than high-energy phosphate change in early anoxia and much smaller in extended anoxia. The patterns of guanosine triphosphate and uridine triphosphate changes are more complex than adenosine triphosphate changes. Nicotinamideadenine dinucleotide levels are steady until late anoxia, at which time they decrease slightly. Cytidine monophosphate is the only cytidine nucleotide detected. Inosine nucleotide concentrations in control animals were below the limit of the method, but in late anoxia inosine monophosphate appeared. The data show that the energy flow through the phosphates in brain is rapid and involves phosphate compounds other than the acid-soluble nucleotides and phosphoryl-creatine.