EFFECTS OF T-BUTYL HYDROGEN-PEROXIDE ON SINGLE SR CALCIUM-RELEASE CHANNELS

Using lipid bilayer reconstitution technique, we investigated the oxid ation effect of t-butyl hydrogen peroxide (tBHP) on the single channel activity of the sarcoplasmic reticulum (SR) calcium release channels isolated from canine latissimus dorsi muscles. When 0.7% tBHP was adde d in the cytosolic side, the channel activity became suppressed (n=7), and it was recovered by changing the solution to the control solution . The suppression was due to the change in the gating mode of the chan nel: before tBHP the channel opened to four sub-conductance levels but it opened to only one level after tBHP. These effects by tBHP were di fferent from the previous finding using hydrogen peroxide (H2O2), whic h may be explained by different oxidation patterns between the onto ox idants.