Restoration of red cell catalase activity by glucose metabolism after exposure to a vitamin K analog
| Autor: | Stephen Gene Sullivan, Arnold Stern, Sandra McMahon |
|---|---|
| Rok vydání: | 1979 |
| Předmět: |
Blood Glucose
Erythrocytes Time Factors Oxidative phosphorylation Pentose phosphate pathway Carbohydrate metabolism In Vitro Techniques Biochemistry chemistry.chemical_compound Humans Incubation Methemoglobin Pharmacology Red Cell biology Superoxide Catalase NAD chemistry biology.protein Pyrimidine Nucleotides Energy source NADP Naphthoquinones |
| Zdroj: | Biochemical pharmacology. 28(23) |
| ISSN: | 0006-2952 |
| Popis: | The relationship between catalase and reducing equivalents in the red cell was studied by first exposing cells to an oxidative insult and then adding glucose as an energy source to facilitate recovery from the oxidative insult. Oxidative damage was produced by incubation of red cells with either 2 × 10 −6 M or 4 × 10 −5 M 1, 4-naphthoquinone-2-sulfonic acid, a vitamin K analog which generates Superoxide in the presence of oxyhemoglobin. After a 90 min incubation, cellular catalatic activity decreased to about 30 per cent of the original activity, NADH content was decreased to about 40 per cent, and NADPH content decreased to 10 per cent. At 90 min, d -glucose was added to a concentration of 5 mM. After a further 90 min incubation, red cells originally treated with the low concentration of quinone recovered catalatic activity to 70 per cent of the original activity, NADH to 60 per cent of the starting content, and NADPH content rose above 100 per cent. Red cells incubated with the higher quinone concentration did not recover catalatic activity or reduced nucleotide content. The data imply that catalase accumulates as the peroxidatic intermediate, Compound II, in the absence of a sufficient concentration of reducing equivalents. If oxidative damage is mild enough so that the glycolytic pathway and hexose monophosphate shunt can still restore an adequate level of reducing equivalents after the addition of glucose, then catalatic activity will be restored as the concentrations of ferricatalase and Compound I increase. The results indicate that catalase may function both peroxidatically and catalatically in the red cell. |
| Databáze: | OpenAIRE |
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