pH dependence of lipid peroxidation and albumin oxidative modification: possible implications to the pH paradox
| Autor: | Afonso Fernandes, P M Filipe, C F Manso |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Programmed cell death
Antioxidant Chromatography Diene Physiology Chemistry medicine.medical_treatment Radical Biochemistry (medical) Clinical Biochemistry Albumin chemistry.chemical_element Cell Biology Oxidative phosphorylation Biochemistry Copper 030218 nuclear medicine & medical imaging Lipid peroxidation 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine medicine 030217 neurology & neurosurgery |
| Zdroj: | Redox Report. 1:139-144 |
| ISSN: | 1743-2928 1351-0002 |
| DOI: | 10.1080/13510002.1995.11746972 |
| Popis: | The hydrogen ion concentration may have an important influence in biological free radical reactions. We studied the effect of an acidic pH on two models of free radical-mediated damage: copper-induced lipid peroxidation in plasma and copper/hydrogen peroxide-induced oxidative modification of albumin. A reduction of pH from 7·4 to 6·6 decreased diene conjugation by 32%, thiobarbituric acid-reactive substances formation by 25% and fluorescence generation by 53% in plasma exposed to cupric chloride. At pH values lower than 6·6 an even greater inhibition of lipid peroxidation in plasma was obtained. Visible fluorescence development in albumin by exposure to site-specific generation of free radicals was also increasingly reduced by decreasing pH values. From pH 7·4 to 6·6 there was a 50% fluorescence generation inhibition. The observed partial protection of lipids and proteins against oxidative damage by an acidic pH alerts to the need for rigorously controlling the pH values when assaying compounds for antioxidant properties in vitro. It may also contribute to the explanation for the protective effect of an acidic pH against anoxic cell injury and for cell death that is precipitated by a rapid return to a normal pH following reperfusion (the 'pH paradox'). |
| Databáze: | OpenAIRE |
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