Fig. 3

Impact of Akt inhibition on insulin-induced cardiac contraction. Adult rat ventricular cardiomyocytes (ARVM) were analysed either without pre-treatment (blank bars) or pre-treated with 10 µM of the specific Akt-inhibitor triciribine (filled bars) for 30 min. Subsequently, ARVM were treated with either 100 nM insulin or insulin analogues for 10 min to investigate the insulin signalling pathway after triciribine treatment (a). Furthermore, ARVM were treated with 100 nM of insulin or insulin analogues or 10 nM isoproterenol and paced at 1 Hz, 15 V, 0.5 ms with the IonOptix Myopacer Cell Stimulator System to assess the sarcomeric shortening (b), departure velocity (c) and return velocity (d). In each condition at least 10 contractions of 10–14 cardiomyocytes were measured. Data represent mean values ± SEM, n = 3–5, *p < 0.05 vs. basal (treated). Regular insulin Ins, isoproterenol iso, active metabolite of insulin glargine IGlaM1, insulin degludec IDeg