DM, fractional conductance, and Ca²⁺ release appear unrelated to the K_d of calcins. (A) Plot of DM versus K_d of [³H]ryanodine binding. The DMs have a poor correlation with the binding affinity (r² = 0.15). (B) Subconductance versus K_d of [³H]ryanodine binding. The position of subconductance induced by calcin is unrelated to the K_d of [³H]ryanodine binding (r² = 0.07). (C) Ca²⁺ release versus [³H]ryanodine binding. No correlation is seen between calcin concentration that induces Ca²⁺ release and K_d of [³H]ryanodine binding (r² = 0.04).