Na-K-ATPase inhibitor dissociated from hypertension-associated plasma protein
| Autor: | E W, Weiler, F, Khalil-Manesh, H C, Gonick, B A, Prins, R E, Purdy, D K, Sensharma |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Male
4-Nitrophenylphosphatase Digoxin Radioimmunoassay Blood Proteins In Vitro Techniques Tritium Binding Competitive Mass Spectrometry Femoral Artery Molecular Weight Vasoconstriction Hypertension Animals Humans Electrophoresis Polyacrylamide Gel Rabbits Enzyme Inhibitors Sodium-Potassium-Exchanging ATPase Ouabain |
| Zdroj: | American journal of hypertension. 12(4 Pt 1) |
| ISSN: | 0895-7061 |
| Popis: | It has been demonstrated that human plasma contains a low molecular weight sodium-potassium-stimulated adenosine triphosphatase (Na-K-ATPase) inhibitor, which can be dissociated from a circulating protein with a molecular weight of approximately 12,000 daltons. The dissociated factor was found to have a molecular weight500 daltons, and shared many characteristics with ouabain. Similar to ouabain, this factor was found to be a potent inhibitor of both the Na-K-ATPase and potassium-stimulated para-nitrophenyl phosphatase (K-pNPPase) enzyme systems, and to bind to both high- and low-affinity binding sites on Na-K-ATPase, but unlike ouabain did not cross-react with digoxin antibody. The factor was further separated by HPLC and electrochemical detection into two active compounds (p-NKAI-1 and p-NKAI-2). P-NKAI-1 was demonstrated on mass spectroscopy to have a molecular weight of 408 daltons. In a vasoconstrictor assay employing rabbit femoral artery segments, this compound was a direct vasoconstrictor and potentiated the vasoconstriction produced by norepinephrine. It behaved similarly to ouabain in counteracting the relaxing effect on rabbit femoral artery of increasing potassium concentrations in the tissue bath. |
| Databáze: | OpenAIRE |
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