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HIDALGO,CECILIA; ARACENA,PAULA; SANCHEZ,GINA; DONOSO,PAULINA. |
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+]... |
Tipo: Journal article |
Palavras-chave: Redox state; Ryanodine receptors; Sarcoplasmic reticulum; Calcium release kinetics; Mg2+ inhibition; S-nitrosoglutathione. |
Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602002000200009 |
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