Figure 1. Effect of propofol on the rate constant of Calcium2+ efflux from sarcoplasmic reticulum vesicles. Malignant hyperthermia (MH)-susceptible (A) and normal (B) vesicles were loaded with Calcium sup 2+, Calcium2+ efflux was measured after dilution into a medium containing various concentrations of propofol and 6 micro Meter Calcium sup 2+(filled circles) to activate ryanodine receptor (RYR)-mediated Calcium2+ efflux, or 10 mM EGTA, 10 mM MgCl2, 10 micro Meter ruthenium red (open circles) to inhibit RYR-mediated efflux. (Insets) Difference between Calcium2+ efflux in the presence of 6 micro Meter Calcium2+ and in the presence of RYR channel inhibitors. Points are means plus/minus SE of duplicate measurements from four MH- susceptible and four normal preparations.