Concentration response relationships of the sinus HR response to the muscarinic receptor agonist Acetylcholine (ACh, A) and to the β-adrenergic agonist Isoproterenol (Iso, B). Compared to wild-type (WT) hearts, Casq2 null hearts (CASQ−/−) exhibited an enhanced HR response to ACh, whereas the HR response to β-adrenergic stimulation with Iso was impaired. Figure modified from (8).
With permission: Glukhov AV, Kalyanasundaram A, Lou Q, Hage LT, Hansen BJ, Belevych AE, Mohler PJ, Knollmann BC, Periasamy M, Gyorke S, et al. Calsequestrin 2 deletion causes sinoatrial node dysfunction and atrial arrhythmias associated with altered sarcoplasmic reticulum calcium cycling and degenerative fibrosis within the mouse atrial pacemaker complex. Eur Heart J. 2013.