SULFHYDRYL OXIDATION INDUCES CALCIUM RELEASE FROM FRAGMENTED SARCOPLASMIC-RETICULUM EVEN IN THE PRESENCE OF GLUTATHIONE

Alcian blue and plumbagin induced transient Ca2+ release from fragment ed sarcoplasmic reticulum. Dithiothreitol (DTT) and glutathione (GSH) partially blocked Ca2+ release induced by these oxidizing compounds. P retreatment of alcian blue and plumbagin with DTT or GSH for more than 1 min was required to abolish the ability of the oxidizing compounds to release Ca2+. Mg2+ and ruthenium red completely blocked alcian blue - and plumbagin-induced Ca2+ release. These results suggest that oxida tion of sulfhydryls on Ca2+ release channels induces Ca2+ release even in the presence of GSH in situ.