GCG and Arrhythmia: Please also note that the isoprenaline-induced short-lasting, spontaneous contractions which appear as arrhythmias in the lower ordinate tracing of Figure 7D. In summary, 100 nM of glucagon did not alter the force of contraction in electrically stimulated right atrial preparations of adult mice (amounting 102 ± 9% of pre-glucagon value, p > 0.05, n = 5).