Figure 3
Nur77-KO cardiomyocytes exhibit prolonged action potentials.
Action potential (AP) measurements were performed in WT (n = 20) and Nur77-KO (n = 18) cardiomyocytes isolated from 3 mice of each group. (a) Representative APs at 6 Hz. Inset shows the maximal AP upstroke velocity (dV/dtmax). (b) Average AP characteristics at 6 Hz. No differences were observed in resting membrane potential (RMP), AP amplitude (APA) or AP duration (APD) at 20% and 50% repolarization. APD90 was significantly longer in Nur77-KO cardiomyocytes. (c) APD90 was significantly enhanced in Nur77-KO cardiomyocytes at all measured stimulation frequencies. Early after-depolarisations (inset; arrow) were observed only in a subset of Nur77-KO cardiomyocytes at 1 and 2 Hz. Data presented as mean ± SEM; *p < 0.05.
