Fig. 3. Dose dependence of 4-chloro-m-cresol (4CmC)-induced adenosine in lymphocyte cells from normal (open circle , n = 7) and malignant hyperthermia-susceptible swine carrying the Arg615Cys mutation in the ryanodine receptor type 1 (filled circle , n = 7). Sample adenosine concentrations were normalized to reflect value per 106cells. Cells (1-2 × 106) in suspension in normal Hank's balanced salt solution containing adenosine deaminase inhibitor (erythro-9(2-hydroxy-3-nonyl) adenine, 0.1 mm) were incubated at 37°C for 10 min followed by treatment for additional 30 min with different 4CmC concentrations as indicated. *4CmC-induced adenosine levels in presence of 0.5, 1, 2, or 5 mm are significantly higher in the MHS group than in the normal control group; P values were 0.0035, 0.0035, 0.0017, and 0.0008, respectively.