Oxidation of Tris to One-Carbon Compounds in a Radical-Producing Model System,in Microsomes,in Hepatocytes and in Rats |
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Abstract: | The buffer substance tris(hydroxymethyl)aminomethane (Tris) is converted to formaldehyde in an hydroxyl radical producing model system and in rat liver microsomes, and to CO2 in rat hepatocytes and in the intact rat. In microsomes, formaldehyde formation from Tris is inhibited by catalase, by the antioxidant propylgallate and by the iron chelator deferoxamine, formaldehyde formation is stimulated by the addition of Fe (II) EDTA. In hepatocytes, the formation of 14C] CO2 from 14C] Tris is inhibited by propylgallate and by the iron chelator o-phenanthroline and is stimulated by the presence of a xanthine oxidase system plus Fe (II) EDTA in the medium. In the intact rat, the administration of 14C] Tris results in the exhalation of 14C] CO2. The results indicate that an oxidant formed via a Fenton-type reaction, possibly the hydroxyl radical, may be involved in the formation of one-carbon compounds from Tris. |
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Keywords: | Hydroxyl radicals tris(hydroxymethyl)aminomethane hepatocytes formaldehyde production CO2 production propyl gallate ortho-phenanthroline |
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