Abstract
1. Pig aortic endothelial and smooth-muscle cells in culture rapidly catabolize exogenous ATP, ADP or AMP. 2. In both cell types catabolism is due to Mg2+-stimulated ectoenzymes. 3. Inhibition and substrate-specificity studies suggest that both cell types possess three distinct ectonucleotidases, namely nucleoside triphosphatase (EC 3.6.1.15), nucleoside diphosphatase (EC 3.6.1.6) and 5'-nucleotidase (EC 3.1.3.5), as well as nucleoside diphosphate kinase (EC 2.7.4.6). 4. These ectonucleotidase systems could be of importance in the regulation of neurotransmission, blood platelet function and vasodilation.
MeSH terms
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Acid Anhydride Hydrolases*
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Adenine Nucleotides / metabolism*
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Animals
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Aorta / enzymology*
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Cells, Cultured
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Endothelium / enzymology
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Kinetics
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Muscle, Smooth, Vascular / enzymology*
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Nucleoside-Diphosphate Kinase / metabolism*
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Nucleoside-Triphosphatase
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Nucleotidases / metabolism
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Nucleotides / metabolism
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Phosphoric Monoester Hydrolases / metabolism*
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Phosphotransferases / metabolism*
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Substrate Specificity
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Swine
Substances
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Adenine Nucleotides
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Nucleotides
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Phosphotransferases
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Nucleoside-Diphosphate Kinase
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Nucleotidases
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Phosphoric Monoester Hydrolases
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Acid Anhydride Hydrolases
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Nucleoside-Triphosphatase
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nucleoside-diphosphatase