Role of Superoxide Anions in Changes of Endothelial Vasoactive Response during Acute Hyperglycemia
| Autor: | T. C. Wascher, Wolfgang F. Graier, Gert M. Kostner, Karla Posch |
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| Rok vydání: | 1997 |
| Předmět: |
Anions
medicine.medical_specialty Endothelium Swine Endocrinology Diabetes and Metabolism Clinical Biochemistry Probucol Vasodilation Nitric Oxide Biochemistry Superoxide dismutase chemistry.chemical_compound Endocrinology Superoxides Internal medicine Diabetes Mellitus medicine Animals Xanthine oxidase Aorta Cells Cultured Hypoxanthine chemistry.chemical_classification Reactive oxygen species biology Superoxide Biochemistry (medical) General Medicine Glucose medicine.anatomical_structure chemistry Hyperglycemia cardiovascular system biology.protein Calcium Endothelium Vascular Nitric Oxide Synthase Signal Transduction medicine.drug |
| Zdroj: | Europe PubMed Central |
| ISSN: | 1439-4286 0018-5043 |
| DOI: | 10.1055/s-2007-979113 |
| Popis: | The effects of acute hyperglycemia on endothelial Ca2+ signaling, formation of endothelium-derived relaxing factor (EDRF) and bioactivity of EDRF were investigated. Hyperglycemia increased 2,5-tert-butyl-1,4-hydrochinone (BHQ)-initiated Ca2+ signaling and EDRF formation in a concentration-dependent manner. The effect of elevated D-glucose on Ca2+/EDRF response could be diminished by co-incubation with the antioxidants vitamin E, probucol, GSH, vitamin C and superoxide dismutase. Convincingly, hyperglycemic conditions yielded an increase in superoxide anion release from endothelial cells and the superoxide anion-generating mixture xanthine oxidase/hypoxanthine mimicked the effect of hyperglycemia on Ca2+/EDRF signaling. Besides an enhanced formation of the vasodilatatory NO compound EDRF, hyperglycemia enhanced NO degradation by endothelial cells and, thus, reduced bioactivity of EDRF. We suggest that vasoactivity during acute hyperglycemia depends on the superoxide anion scavenging properties of the vascular wall. In acute hyperglycemia and early stages of diabetes, radical scavenging capacity may be suitable to protect NO degradation, resulting in an enhanced vasodilation. In contrast, decreased free radical scavenging properties of the vasculature in prolonged hyperglycemia and in later stages of diabetes might promote NO degradation by an overshoot of superoxide anions, resulting in an attenuation of endothelium-dependent vasodilation. |
| Databáze: | OpenAIRE |
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