ACTIVITY OF SOME ADENINE-NUCLEOTIDE DEGRADATION ENZYMES IN HUMAN ATHEROSCLEROTIC AORTA ENDOTHELIUM

Remarkable activity of various enzymes involved in adenine nucleotide degradation has been revealed in the endothelium recently. Using the h ighly sensitive radiochromatographic methods, and activities of 5'-nuc leotidase, EC: 3.1.3.5. (5'-Nase), adenine deaminase, EC: 3.5.4.4. (AD ase), and purine nucleoside phosphorylase, EC: 2.4.2.5. (PN-Pase) were estimated in the endothelium from normal human aortas characterized b y a regular arrangement of cells and in the endothelium from atheroscl erotic aortas characterized by different size and often multinucleated cells. Activities of 5'-Nase and A Dase in the endothelial cells of a therosclerotic aortas were significantly higher than activities in nor mal ones. However, the activity of PNPase was approximately on the sam e level in both aortas. The above findings indicate a shift in the act ivity of 5'-Nase and ADase, which might be a result of the atheroscler otic process as well as the aggregation of platelets.