dc.creator | HIDALGO,CECILIA | |
dc.creator | ARACENA,PAULA | |
dc.creator | SANCHEZ,GINA | |
dc.creator | DONOSO,PAULINA | |
dc.date | 2002-01-01 | |
dc.date.accessioned | 2019-05-02T21:21:05Z | |
dc.date.available | 2019-05-02T21:21:05Z | |
dc.identifier | https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0716-97602002000200009 | |
dc.identifier.uri | http://revistaschilenas.uchile.cl/handle/2250/81412 | |
dc.description | In skeletal and cardiac muscle cells, specific isoforms of the Ryanodine receptor channels mediate Ca2+ release from the sarcoplasmic reticulum. These channels are highly susceptible to redox modifications, which regulate channel activity. In this work, we studied the effects of Ca2+ (endogenous agonist) and Mg2+ (endogenous inhibitor) on the kinetics of Ca2+ release from sarcoplasmic reticulum vesicles isolated from skeletal or cardiac mammalian muscle. Native skeletal vesicles exhibited maximal stimulation of release kinetics by 10-20 µM [Ca2+], whereas in native cardiac vesicles, maximal stimulation of release required only 1 µM [Ca2+]. In 10 µM [Ca2+], free [Mg2+] < 0.1 mM produced marked inhibition of release from skeletal vesicles but free [Mg2+] 0.8 mM did not affect release from cardiac vesicles. Incubation of skeletal or cardiac vesicles with the oxidant thimerosal increased their susceptibility to stimulation by Ca2+ and decreased the inhibitory effect of Mg2+ in skeletal vesicles. Sulfhydryl-reducing agents fully reversed the effects of thimerosal. The endogenous redox species, glutathione disulfide and S-nitrosoglutathione, also stimulated release from skeletal sarcoplasmic reticulum vesicles. In 10 µM [Ca2+], 35S-nitrosoglutathione labeled a protein fraction enriched in release channels through S-glutathiolation. Free [Mg2+] 1 mM or decreasing free [Ca2+] to the nM range prevented this reaction. Possible physiological and pathological consequences of redox modification of release channels on Ca2+ signaling in heart and muscle cells are discussed | |
dc.format | text/html | |
dc.language | en | |
dc.publisher | Sociedad de Biología de Chile | |
dc.relation | 10.4067/S0716-97602002000200009 | |
dc.rights | info:eu-repo/semantics/openAccess | |
dc.source | Biological Research v.35 n.2 2002 | |
dc.subject | Redox state | |
dc.subject | Ryanodine receptors | |
dc.subject | sarcoplasmic reticulum | |
dc.subject | calcium release kinetics | |
dc.subject | Mg2+ inhibition | |
dc.subject | S-nitrosoglutathione | |
dc.title | Redox regulation of calcium release in skeletal and cardiac muscle | |