| Autor: |
Henning Petermann, I. Wenz, P. Arese, U. Till |
| Rok vydání: |
1981 |
| Předmět: |
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| Zdroj: |
Cell Calcium. 2:495-507 |
| ISSN: |
0143-4160 |
| DOI: |
10.1016/0143-4160(81)90009-9 |
| Popis: |
Human red cells (RBC) were loaded with moderate amounts of Ca 2+ by the ionophore A23187. Quantitative relationships between Ca 2+ -loading, ATP consumption and glycolytic flux were established. 1. Ca 2+ -loading is accompanied by ATP depletion. A maximum ATP consumption of approximately 10 mmoles/l RBC/h was estimated. 2. There is a positive correlation between lactate formation and Ca 2+ -loading. This is linear from 1.4 to about 4 mmoles lactate/l RBC/h. 3. Ca 2+ -induced glycolytic stimulation seems not to be mediated by adenine nucleotides. A wide range of energy charges and very different adenine nucleotide patterns were associated with the same stimulation of lactate production. 4. The turnover of the (Ca 2+ -Mg 2+ )-ATPase and its share in the Ca 2+ -stimulated ATP consuming processes were estimated with inhibitors. 1 mM La 3+ inhibited both Ca 2+ -outward transport and ATP consumption by 80%. The remaining 20% of the ATP consumption was accounted for by the (Na + -K + )-ATPase. 5. A Ca 2+ extrusion to ATP consumption molar ratio of 2:1 was found. However, when ATP consumption was due to the breakdown of previously accumulated glycolytic intermediates, the ratio dropped to about 1. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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