Treatment with tetracaine (TTC, a classic RyR antagonist), in mice in vivo significantly attenuated CH-induced increase in Bmax in SR preparations from PASMCs (0.34 ± 0.06 versus 0.6 ± 0.1, P < 0.05, Fig. 3a). Here, RYR1 is linked to cyclic hematopoiesis.