title: Functional evidence for nitric oxide production by skeletal-muscle mitochondria from lipopolysaccharide-treated mice.
abstract: The possible existence of a mitochondrially localized nitric oxide (NO) synthase (mtNOS) is controversial. To clarify this, we studied the ability of intact mitochondria to generate NO and the effect of mitochondrial NO on respiration. Respiratory rates and oxygen kinetics (P(50) values) were determined by high-resolution respirometry in skeletal-muscle mitochondria from control mice and mice injected with Escherichia coli lipopolysaccharide (LPS). In the presence of the NOS substrate L-arginine, mitochondria from LPS-treated mice had lower respiration rates and higher P(50) values than control animals. These effects were prevented by the NOS inhibitor L-NMMA. Our results suggest that mitochondrially derived NO is generated by an LPS-inducible NOS protein other than iNOS and modulates oxygen consumption in mouse skeletal muscle.
authors.affiliation: Department of Regenerative Cardiology, Centro Nacional de Investigaciones Cardiovasculares, Melchor Fernández Almagro 3, 28029 Madrid, Spain.
authors.forename: Enara
authors.initials: E
authors.lastname: Aguirre
authors.forename: Elia
authors.initials: E
authors.lastname: López-Bernardo
authors.forename: Susana
authors.initials: S
authors.lastname: Cadenas
mesh_terms: D000818:Animals; D019069:Cell Respiration; D004926:Escherichia coli / Q000737:chemistry / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008931:Mitochondria, Muscle / Q000187:drug effects* / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism
chemical_list: D008070:Lipopolysaccharides; D009569:Nitric Oxide; D010100:Oxygen