Oxidative modification of ion channel activity of ryanodine receptor.

The ryanodine receptor (RyR) is involved in the physiological Ca2+ release from the sarcoplasmic reticulum in both skeletal and cardiac muscles. The redox regulation is a plausible endogenous regulatory mechanism of the RyR. Sulfhydryl oxidation or S-nitrosylation of the cardiac RyR has been reported to activate the channel. Our laboratory demonstrated that hydroxyl radicals also activate the cardiac Ca2+-release channel activity, likely through the modification of sulfhydryl groups of the RyR.