A mitochondrial role for catabolism of nitric oxide in cardiomyocytes not involving oxymyoglobin.
The maximal concentration of nitric oxide (NO) developing in cultured cells following stimulation of endogenous NO synthases was shown to be submicromolar by NO-selective microelectrode measurements. In electron paramagnetic resonance experiments with isolated and finely divided pericardium, NO was found to react with oxymyoglobin to form metmyoglobin provided that NO was supplied at concentrations in excess of a few micromolar. However, at NO concentrations achievable by endogenous sources, this reaction did not take place to any measurable extent. Oxidative conversion of NO to nitrite ion by cytochrome c oxidase appears to be the most plausible route for cellular catabolism of NO.
Peterson
Jim
J
Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213, USA. jamesp@andrew.cmu.edu
Kanai
Anthony J
AJ
Pearce
Linda L
LL
D000818:Animals; D002478:Cells, Cultured; D004563:Electrochemistry / Q000295:instrumentation; D004578:Electron Spin Resonance Spectroscopy; D008786:Metmyoglobin / Q000378:metabolism; D051379:Mice; D008839:Microelectrodes; D008929:Mitochondria, Heart / Q000378:metabolism*; D009211:Myoglobin / Q000502:physiology*; D009569:Nitric Oxide / Q000378:metabolism*; D009994:Osmolar Concentration; D010496:Pericardium / Q000378:metabolism; D051381:Rats
D009211:Myoglobin; C017595:oxymyoglobin; D008786:Metmyoglobin; D009569:Nitric Oxide