SUBCELLULAR-DISTRIBUTION OF CERTAIN ENZYMES OF THE ADENOSINE SYSTEM IN THE HYPOTHALAMUS AND HIPPOCAMPUS OF THE RAT-BRAIN

The subcellular distribution of 5'-nucleotidase and adenosine deaminase in the hypothalamus and hippocampus of the rat brain was investigated. It was shown that the 5'-nucleotidase activity in the hippocampus is significantly higher than in the hypothalamus, whereas the adenosine deaminase activity is approximately twice as high in the hypothalamus. In an investigation of the subcellular distribution, 5'-nucleotidase and adenosine deaminase was detected in all the fractions studied: nuclear, soluble, myelin, synaptic membranes, synaptosomes, and "pure" mitochondria. Moreover, the highest 5'-nucleotidase activity was detected in the myelin fraction and the fraction of synaptic membranes, both in the hypothalamus and in the hippocampus. The highest adenosine deaminase activity was established in the soluble fraction of the structures studied. In the synaptic membranes and synaptosomes the activity of the enzymes was approximately half as great.