Figure 3. MCa does not modify [³H]ryanodine binding on RyR2.

[³H]Ryanodine binding on skeletal and cardiac vesicles was measured in the presence of 5 nM [³H]ryanodine and various concentrations of MCa as described in the Experimental section. Multiplication factor of [³H]ryanodine binding on skeletal vesicles (○) and cardiac vesicles (●) are presented as a function of MCa concentration. Non-specific binding remained constant independently of MCa concentrations and represented less than 8% of total binding. Each point was performed in triplicate. Data obtained with skeletal vesicles were fitted with the following equation: y=y₀+ax/b+x with a=7.205±0.564 and b=25.58±9.42.