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MAXIMUM ACTIVITIES, PROPERTIES AND DISTRIBUTION OF 5’NUCLEOTIDASE, ADENOSINE KINASE AND ADENOSINE DEAMINASE IN RAT AND HUMAN BRAIN
Article first published online: 5 OCT 2006
Journal of Neurochemistry
Volume 33, Issue 2, pages 553–558, August 1979
How to Cite
Phillips, E. and Newsholme, E. A. (1979), MAXIMUM ACTIVITIES, PROPERTIES AND DISTRIBUTION OF 5’NUCLEOTIDASE, ADENOSINE KINASE AND ADENOSINE DEAMINASE IN RAT AND HUMAN BRAIN. Journal of Neurochemistry, 33: 553–558. doi: 10.1111/j.1471-4159.1979.tb05187.x
- Issue published online: 5 OCT 2006
- Article first published online: 5 OCT 2006
- (Received 27 September 1978. Revised 9 March 1979. Accepted 26 March 1979)
Abstract— The maximum activities of 5’nucleotidase, adenosine kinase and adenosine deaminase have been measured in several areas of rat and human brain. There is no major difference between the activities of nucleotidase and kinase between rat and human brain, but the activity of deaminase is considerably higher in human brain. The activities of all these enzymes are similar in three areas of rat brain and nine areas of human brain, except for hind brain of the human, which has a low activity of adenosine deaminase. This variation may indicate the existence of different steady-state concentrations of adenosine in certain areas of the brain.
Subcellular fractionation of different areas of rat brain showed that, whereas adenosine kinase and deaminase activities were located mainly in the soluble fractions, 5’nucleotidase was present in all subcellular fractions (i.e. membrane, synaptosomal, mitochondrial and soluble). In particular, there was no major localisation within the synaptosomal fraction. Thus it is unlikely that the regulation of the activities of these enzymes is dependent upon changes within a specific compartment (e.g. synaptosomes) in the brain.