| Homogentisic acid autoxidation and oxygen radical generation: implications for the etiology of alkaptonuric arthritis. | |
| | |
MedLine Citation:
|
PMID: 3121448 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
The metabolic disorder, alkaptonuria, is distinguished by elevated serum levels of 2,5-dihydroxyphenylacetic acid (homogentisic acid), pigmentation of cartilage and connective tissue and, ultimately, the development of inflammatory arthritis. Oxygen radical generation during homogentisic acid autoxidation was characterized in vitro to assess the likelihood that oxygen radicals act as molecular agents of alkaptonuric arthritis in vivo. For homogentisic acid autoxidized at physiological pH and above, yielding superoxide (O2-)2 and hydrogen peroxide (H2O2), the homogentisic acid autoxidation rate was oxygen dependent, proportional to homogentisic acid concentration, temperature dependent and pH dependent. Formation of the oxidized product, benzoquinoneacetic acid was inhibited by the reducing agents, NADH, reduced glutathione, and ascorbic acid and accelerated by SOD and manganese-pyrophosphate. Manganese stimulated autoxidation was suppressed by diethylenetriaminepentaacetic acid (DTPA). Homogentisic acid autoxidation stimulated a rapid cooxidation of ascorbic acid at pH 7.45. Hydrogen peroxide was among the products of cooxidation. The combination of homogentisic acid and Fe3+-EDTA stimulated hydroxyl radical (OH.) formation estimated by salicylate hydroxylation. Ferric iron was required for the reaction and Fe3+-EDTA was a better catalyst than either free Fe3+ or Fe3+-DTPA. SOD accelerated OH. production by homogentisic acid as did H2O2, and catalase reversed much of the stimulation by SOD. Catalase alone, and the hydroxyl radical scavengers, thiourea and sodium formate, suppressed salicylate hydroxylation. Homogentisic acid and Fe3+-EDTA also stimulated the degradation of hyaluronic acid, the chief viscous element of synovial fluid. Hyaluronic acid depolymerization was time dependent and proportional to the homogentisic acid concentration up to 100 microM. The level of degradation observed was comparable to that obtained with ascorbic acid at equivalent concentrations. The hydroxyl radical was an active intermediate in depolymerization. Thus, catalase and the hydroxyl radical scavengers, thiourea and dimethyl sulfoxide, almost completely suppressed the depolymerization reaction. The ability of homogentisic acid to generate O2-, H2O2 and OH. through autoxidation and the degradation of hyaluronic acid by homogentisic acid-mediated by OH. production suggests that oxygen radicals play a significant role in the etiology of alkaptonuric arthritis. |
| | |
Authors:
|
J P Martin; B Batkoff |
Related Documents
:
|
21343658 - Long-term effect of an enteral diet with a different n-6/n-3 ratio on fatty acid compos... 11902978 - Free radical studies of ellagic acid, a natural phenolic antioxidant. 21557608 - Hydrogen generation by hangman metalloporphyrins. 16380258 - Novel dual inhibitors of calpain and lipid peroxidation with enhanced cellular activity. 8011678 - Biosynthesis of phospholipid molecular species in isolated liver cells studied by combi... 10542058 - Differential in vitro activation and deactivation of cysteine proteinases isolated duri... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
|
Title: Free radical biology & medicine Volume: 3 ISSN: 0891-5849 ISO Abbreviation: Free Radic. Biol. Med. Publication Date: 1987 |
Date Detail:
|
Created Date: 1988-02-08 Completed Date: 1988-02-08 Revised Date: 2007-11-14 |
Medline Journal Info:
|
Nlm Unique ID: 8709159 Medline TA: Free Radic Biol Med Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 241-50 Citation Subset: IM |
Affiliation:
|
Department of Biology, William Marsh Rice University, Houston, TX 77005. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Alkaptonuria
/
complications,
metabolism* Animals Arthritis / etiology, metabolism* Ascorbic Acid / metabolism Edetic Acid / pharmacology Free Radicals Homogentisic Acid / metabolism* Hyaluronic Acid / metabolism Oxidation-Reduction Oxygen Consumption* Polarography Pyrogallol / metabolism Superoxide Dismutase / metabolism |
| Grant Support | |
ID/Acronym/Agency:
|
AI-19695/AI/NIAID NIH HHS |
| Chemical | |
Reg. No./Substance:
|
0/Free Radicals; 451-13-8/Homogentisic Acid; 50-81-7/Ascorbic Acid; 60-00-4/Edetic Acid; 87-66-1/Pyrogallol; 9004-61-9/Hyaluronic Acid; EC 1.15.1.1/Superoxide Dismutase |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Various means of integration of the expressible human dihydrofolate reductase gene into the Bacillus...
Next Document: Mucosal polyamine profile in normal and adapting (hypo and hyperplastic) intestine: effects of DFMO ...