Posted by raybakes on October 17, 2004, at 14:34:12
In reply to Re: dopamine oxidation » raybakes, posted by Larry Hoover on October 17, 2004, at 14:04:51
> Actually, glutathione et al keep them from forming in the first place.Hi Lar, I agree that glutathione would keep them from forming, but this abstract seems to imply that they are detoxified by glutathione when they do form...couldn't read Dr Pall's article, as it needed a password :( have heard a bit about his ideas about peroxynitrite, though.
Glutathione transferases catalyse the detoxication of oxidized metabolites (o-quinones) of catecholamines and may serve as an antioxidant system preventing degenerative cellular processes.
Unit of Biochemical Toxicology, Department of Biochemistry, Stockholm University, Wallenberg Laboratory, S-106 91 Stockholm.o-Quinones are physiological oxidation products of catecholamines that contribute to redox cycling, toxicity and apoptosis, i.e. the neurodegenerative processes underlying Parkinson's disease and schizophrenia. The present study shows that the cyclized o-quinones aminochrome, dopachrome, adrenochrome and noradrenochrome, derived from dopamine, dopa, adrenaline and noradrenaline respectively, are efficiently conjugated with glutathione in the presence of human glutathione transferase (GST) M2-2. The oxidation product of adrenaline, adrenochrome, is less active as a substrate for GST M2-2, and more efficiently conjugated by GST M1-1. Evidence for expression of GST M2-2 in substantia nigra of human brain was obtained by identification of the corresponding PCR product in a cDNA library. Glutathione conjugation of these quinones is a detoxication reaction that prevents redox cycling, thus indicating that GSTs have a cytoprotective role involving elimination of reactive chemical species originating from the oxidative metabolism of catecholamines. In particular, GST M2-2 has the capacity to provide protection relevant to the prevention of neurodegenerative diseases.
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> Oxidative stress plays havoc with your sulphur metabolism. So, cysteine, carnitine, taurine, glutathione, SAMe....many key molecules get trashed because sulphur gets trashed before carbon. The reason many antixidants have sulphur atoms is sacrificial. Selenium substitutes for sulphur to become even more sacrificial (as in seleno-cysteine). If there isn't enough sulphur to martyr itself on our behalf, other stuff gets mucked right up, or sulphur-bearing molecules we need for other purposes get destroyed instead.
Thanks for that info...like the fact that selenium, sulphur and oxygen are all related to each other on the periodic table - makes sense that they all work together!Ray
poster:raybakes
thread:404137
URL: http://www.dr-bob.org/babble/alter/20040928/msgs/404167.html