Differential subunit composition of the G protein–activated inward-rectifier potassium channel during cardiac development
J. Clin. Invest. Bernd K. Fleischmann, et al. 114:994 doi:10.1172/JCI15925 [Go to this article.]

Figure 1
Chronotropy differs between early- and late-stage atrial cardiomyocytes. (A) Spontaneous APs are distinctly slowed by CCh (1 μM) in early- (left panel) and late-stage (right panel) cardiomyocytes. APs were recorded under current-clamp conditions; CCh was bath applied. (B) Percentage of cells displaying chronotropic effect and membrane hyperpolarization following application of CCh. Note that only 60% of early-stage cells display hyperpolarization upon application of CCh. (C) AP frequency of early- and late-stage cardiomyocytes before and after application of CCh; data are mean ± SEM of 8 and 9 experiments (P = 0.016 for control and P = 0.022 for CCh, unpaired Student’s t test). (D) Hyperpolarization induced by CCh in early and late stage cardiomyocytes; data are mean ± SEM of 6 and 9 experiments, respectively (P = 0.002, unpaired Student’s t test). Asterisks denote statistically significant difference.