Reduction of NO-induced methemoglobinemia requires extremely high doses of ascorbic acid in vitro
| Autor: | Jörg Dötsch, S. Demirakça, A. Cryer, Wolfgang Rascher, P. G. Kühl, Jörg Hänze |
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| Rok vydání: | 1998 |
| Předmět: |
Adult
medicine.medical_specialty Erythrocytes Time Factors Ascorbic Acid In Vitro Techniques Critical Care and Intensive Care Medicine Methemoglobinemia Nitric Oxide Methemoglobin Nitric oxide chemistry.chemical_compound hemic and lymphatic diseases Internal medicine medicine Humans Incubation Analysis of Variance Dose-Response Relationship Drug business.industry Glutathione medicine.disease Ascorbic acid Red blood cell Endocrinology medicine.anatomical_structure Biochemistry chemistry Spectrophotometry Toxicity business Oxidation-Reduction |
| Zdroj: | Intensive care medicine. 24(6) |
| ISSN: | 0342-4642 |
| Popis: | The objective of the present study was to investigate the treatment of nitric oxide (NO)-induced methemoglobinemia by ascorbate and its consequences on red blood cell (RBC) glutathione in vitro. RBC were obtained from five healthy volunteers. The following experiments were carried out: (1) After methemoglobin generation by NO, ascorbate was added (2) RBC were simultaneously exposed to NO and ascorbate (3) Methemoglobin was generated by NO, ascorbate was added and incubation with NO continued. (1) After discontinuation of NO, the mean half life for methemoglobin was reduced from 195 min (controls) to 60 min (10 mM ascorbate) in a dose-dependent manner. (2) Methemoglobin formation after 3 h of NO exposure was 2.7 ± 0.3 % in controls and 1.8 ± 0.1 % with 10 mM ascorbate (p < 0.01). (3) Further methemoglobin formation was inhibited only by 10 mM ascorbate (p < 0.001). NO incubation did not affect RBC glutathione (86.5 ± 19.6 and 86.5 ± 19.6 mg/l, respectively). Treatment with 10 mM ascorbate significantly decreased glutathione (p < 0.002). In vitro, NO-induced methemoglobin formation is significantly decreased only by a high (10 mM) ascorbate concentration. Glutathione, critical for ascorbate activity, is not influenced by NO. |
| Databáze: | OpenAIRE |
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