RYR2 and cyclic hematopoiesis: Herein, using [3H]-ryanodine binding assay, we found that the maximal binding (Bmax) of ryanodine to RyR was significantly increased from 0.49 ± 0.06 (pmol/mg protein) in control PASMCs to 0.7 ± 0.08 (pmol/mg protein) in PASMCs from CH mice (P < 0.05), as shown in Fig. 1a.