title: Effects of moderate electrical stimulation on reactive species production by primary rat skeletal muscle cells: cross talk between superoxide and nitric oxide production.
abstract: The effects of a moderate electrical stimulation on superoxide and nitric oxide production by primary cultured skeletal muscle cells were evaluated. The involvement of the main sites of these reactive species production and the relationship between superoxide and nitric oxide production were also examined. Production of superoxide was evaluated by cytochrome c reduction and dihydroethidium oxidation assays. Electrical stimulation increased superoxide production after 1 h incubation. A xanthine oxidase inhibitor caused a partial decrease of superoxide generation and a significant amount of mitochondria-derived superoxide was also observed. Nitric oxide production was assessed by nitrite measurement and by using 4,5-diaminofluorescein diacetate (DAF-2-DA) assay. Using both methods an increased production of nitric oxide was obtained after electrical stimulation, which was also able to induce an increase of iNOS content and NF-κB activation. The participation of superoxide in nitric oxide production was investigated by incubating cells with DAF-2-DA in the presence or absence of electrical stimulation, a superoxide generator system (xanthine-xanthine oxidase), a mixture of NOS inhibitors and SOD-PEG. Our data show that the induction of muscle contraction by a moderate electrical stimulation protocol led to an increased nitric oxide production that can be controlled by superoxide generation. The cross talk between these reactive species likely plays a role in exercise-induced maintenance and adaptation by regulating muscular glucose metabolism, force of contraction, fatigue, and antioxidant systems activities.
authors: Post-Graduate Program in Human Movement Sciences, Biological Sciences and Health Center, Cruzeiro do Sul University, Sao Paulo, Brazil. rhlamber@yahoo.com.br
authors: Rafael Herling
authors: RH
authors: Lambertucci
authors: Leonardo Dos Reis
authors: Ldos R
authors: Silveira
authors: Sandro Massao
authors: SM
authors: Hirabara
authors: Rui
authors: R
authors: Curi
authors: Gary
authors: G
authors: Sweeney
authors: Tania Cristina
authors: TC
authors: Pithon-Curi
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D045304:Cytochromes c / Q000378:metabolism; D004558:Electric Stimulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004996:Ethidium / Q000031:analogs & derivatives / Q000737:chemistry; D019793:Fluorescein / Q000737:chemistry; D016166:Free Radical Scavengers / Q000494:pharmacology; D008931:Mitochondria, Muscle / Q000378:metabolism; D009119:Muscle Contraction / Q000187:drug effects; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects; D061251:Primary Cell Culture; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects; D013481:Superoxides / Q000378:metabolism*; D013997:Time Factors; D019820:Xanthine / Q000378:metabolism; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: C414689:4,5-diaminofluorescein diacetate; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D016328:NF-kappa B; D009573:Nitrites; C067883:dihydroethidium; D013481:Superoxides; D019820:Xanthine; D009569:Nitric Oxide; D045304:Cytochromes c; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D014969:Xanthine Oxidase; D004996:Ethidium; D019793:Fluorescein