Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Iron was released from ferritin by the catecholamine analog, 6-hydroxydopamine. Iron release was more efficient under nitrogen than in air, suggesting that the hydroquinone has the major role in the process. Superoxide dismutase, alone or in combination with catalase, strongly inhibited 6-hydroxydopamine oxidation and greatly enhanced the amount of ferritin iron release. Catalase alone had a similar, but lesser effect. Iron released from ferritin accelerated the autoxidation of 6-hydroxydopamine. This occurred by a mechanism that was inhibited by a combination of catalase and a chelator, and to a lesser extent by superoxide dismutase. 6-Hydroxydopamine was a good promoter of metal-catalysed lipid peroxidation, and ferritin-iron participated in the process. Superoxide dismutase, and to a lesser extent catalase, stimulated peroxidation catalysed by adventitious levels of iron, but in the presence of ferritin, each enzyme was inhibitory. It appears that the greatly enhanced iron release seen under these conditions accelerated the autoxidation of 6-hydroxydopamine so that less was available to participate in peroxidative reactions. However, when 6-hydroxydopamine autoxidation was prevented by a combination of superoxide dismutase and catalase, lipid peroxidation was also inhibited, suggesting that some intermediate of autoxidation is a further requirement for the process.
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PMID:6-Hydroxydopamine releases iron from ferritin and promotes ferritin-dependent lipid peroxidation. 251 34

The presence of 5-Hydroxydopamine (5-OHDA) and 6-Hydroxydopamine (6-OHDA) in the urine of parkinsonian patients on levodopa medication was reported by Andrew et al. (1993). To answer the question about the putative relevance of 6-OHDA endogenously formed in the brain for the pathogenesis of Parkinson's disease (PD), the chemical mechanisms leading to dopamine-coordinative complexes were investigated in vitro. Kinetic studies of the reaction of dopamine (DA) with dioxygen over the pH range 7.0-9.0, where it reacts spontaneously without the necessity of metal-ion analysis, show that stoichiometric amounts of H2O2 are produced. Pink dopaminochrome, another oxidation product, is not stable and further reacts--without the consumption of dioxygen--to form the insoluble polymeric material known as melanin. Based on these results, the in vitro chemistry of the reactions of DA, 5-OHDA, and 6-OHDA in the presence of Fe3+ and dioxygen are studied. A mechanism for the initiation of a chain reaction is suggested by which excess Fe3+ could arise, and its relevance for the degeneration of dopaminergic neurons in PD is discussed. Detailed studies on the release of ferritin bound iron (0.2-1.4 microM Fe3+) by synthetic DA (200 microM) may provide further insight into the pathogenesis of PD, but further studies are warranted to elucidate the molecular basis of this neurodegenerative disorder of the extrapyramidal system.
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PMID:Chemical evidence for 6-hydroxydopamine to be an endogenous toxic factor in the pathogenesis of Parkinson's disease. 882 Oct 67