title: Inhibition by purine nucleotides of the release of reactive oxygen species from muscle mitochondria: indication for a function of uncoupling proteins as superoxide anion transporters.
abstract: Release of reactive oxygen species (ROS), measured as the sum of hydrogen peroxide (H₂O₂) and superoxide anion radical (O₂·⁻), from respiring rat heart and skeletal muscle mitochondria was significantly decreased by millimolar concentrations of GTP or GDP. Attempts to differentiate between the two forms of ROS showed that the release of O₂·⁻ rather than that of H₂O₂ was affected. Meanwhile, intramitochondrial ROS accumulation, measured by inactivation of aconitase, increased. These results suggest that guanine nucleotides inhibit the release of O₂·⁻ from mitochondria. As these nucleotides are known inhibitors of uncoupling proteins (UCPs), it is proposed that UCPs may function as carriers of O₂·⁻, thus enabling its removal from the matrix compartment.
authors: Nencki Institute of Experimental Biology, Warsaw, Poland. l.wojtczak@nencki.gov.pl
authors: Lech
authors: L
authors: Wojtczak
authors: Magdalena
authors: M
authors: Lebiedzińska
authors: Jan M
authors: JM
authors: Suski
authors: Mariusz R
authors: MR
authors: Więckowski
authors: Peter
authors: P
authors: Schönfeld
mesh_terms: D000818:Animals; D005260:Female; D006153:Guanosine Diphosphate / Q000494:pharmacology*; D006160:Guanosine Triphosphate / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000378:metabolism; D007473:Ion Channels / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008931:Mitochondria, Muscle / Q000187:drug effects* / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013481:Superoxides / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000071256:Uncoupling Protein 1
chemical_list: D007473:Ion Channels; D024101:Mitochondrial Proteins; D017382:Reactive Oxygen Species; D000071256:Uncoupling Protein 1; D013481:Superoxides; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate; D006861:Hydrogen Peroxide