Figure 2. Effects of ATX II (1 [micro sign]M) on the response to halothane using the European Malignant Hyperthermia Group (EMHG) protocol. Preparations of vastus lateralis muscle from six malignant hyperthermia-negative (MHN) and six malignant hyperthermia-susceptible (MHS) participants diagnosed by the EMHG protocol were incubated in the absence or presence of ATX II for 5 min before exposure to halothane, which was administered in twofold increasing concentrations (0.5–3%). Values are shown as the mean and standard deviation bars when the standard deviations exceed the size of the symbol. The y-axis scales for the MHN and MHS participants are different. *Different from in the absence of ATX II (P < 0.05; two-tailed paired t test).