title: Heme oxygenase-1 induction in skeletal muscle cells: hemin and sodium nitroprusside are regulators in vitro.
abstract: The heat shock protein heme oxygenase-1 (HO-1) is regulated by a variety of physiological and pharmacological factors. In skeletal muscle tissue, HO-1 has been shown to be induced only by exercise and electrical stimulation in vivo. Both hemin and sodium nitroprusside (SNP) are potent inducers of HO-1 in other tissues. In this study, we examined the effects of these two agents on HO-1 induction in L6.G8 rat skeletal myoblast cells. Hemin and SNP increased cellular heme oxygenase activity in both a time- and concentration-dependent manner. Increases in the HO-1 mRNA level and protein expression accompanied changes in heme oxygenase activity. The ability of SNP to induce HO-1 in L6.G8 cells was reduced by coincubation with hydroxocobalamin, a known nitric oxide (NO) scavenger, suggesting that NO itself may be involved in HO-1 gene stimulation. These results indicate that HO-1 expression is sensitive to both hemin and SNP in skeletal myoblast cells and may indicate an important regulatory mechanism of heme catabolism in skeletal muscle tissue.
authors.affiliation: Vascular Biology Unit, Department of Surgical Research, Northwick Park Institute for Medical Research, Harrow, Middlesex, HA1 3UJ, United Kingdom.
authors.forename: M J
authors.initials: MJ
authors.lastname: Vesely
authors.forename: D J
authors.initials: DJ
authors.lastname: Exon
authors.forename: J E
authors.initials: JE
authors.lastname: Clark
authors.forename: R
authors.initials: R
authors.lastname: Foresti
authors.forename: C J
authors.initials: CJ
authors.lastname: Green
authors.forename: R
authors.initials: R
authors.lastname: Motterlini
mesh_terms: D000818:Animals; D019256:Cadmium Chloride / Q000494:pharmacology; D002460:Cell Line; D004790:Enzyme Induction; D006419:Heme Oxygenase (Decyclizing) / Q000096:biosynthesis*; D051547:Heme Oxygenase-1; D006427:Hemin / Q000494:pharmacology*; D006879:Hydroxocobalamin / Q000494:pharmacology; D007700:Kinetics; D018482:Muscle, Skeletal / Q000201:enzymology*; D009599:Nitroprusside / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D012333:RNA, Messenger; D009599:Nitroprusside; D006427:Hemin; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; D019256:Cadmium Chloride; D006879:Hydroxocobalamin