Figure 1.

Effect of 20 μM T₁AM on I_Ca-L current in single patch-clamped rat ventricular cardiomyocytes. (A) In control conditions during the inactivation protocol the current evoked from a holding potential (HP) of –45 mV was greater than that evoked from a HP of –75 mV, a process known as facilitation. (B) T₁AM completely suppressed the facilitation phenomenon, and the current amplitude measured at HP –45 mV was 96% of that measured at HP of –75 mV. (C) Inactivation curves of I_Ca-L under control condition and after exposure to T₁AM (n= 4 in each group). Maximal current amplitude was normalized and plotted versus pre-step potential. Further data analysis is reported in the text: under control conditions I_Ca-L inactivated with the typical bi-exponential decay, while in the presence of T₁AM, I_Ca-L inactivated with a mono-exponential decay.