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Fig. 3. Suppression of Ca2+ current (ICa) by diphenyleneiodonium (DPI). (A) Superimposed ICa recorded at 0 mV (holding potential at –40 mV) before and after applications of 3 μM, 30 μM, 100 μM, and 200 μM DPI in the representative ventricular myocytes, showing concentration-dependent inhibition in ICa by DPI. Scale bars indicate 30 ms in x axis and 2 pA/pF in y axis. (B) Comparison of mean peak ICa measured under control conditions and after applications of different concentrations of DPI (0.3 μM, n = 3; 3 μM, n = 6; 30 μM, n = 8; 100 μM, n = 4; 200 μM, n = 3). **p < 0.01, *p < 0.05 vs. control (Con). Paired t-test. (C) Concentration-dependence curve for % inhibition in ICa versus concentrations of DPI. Plot was fit with Hill equation (Hill coefficient = 0.68). (D) Superimposed ICa measured at voltage steps ranging –40 to +70 mV (holding at –40 mV) with 10-mV-increment before (Control) and after application of 30 μM DPI in a representative ventricle cell. (E) Current-voltage relationships of averaged ICa at the step potentials in the control condition and after exposure to 30 μM DPI (n = 3). Cells were dialyzed with 15 mM EGTA containing internal solutions.
Korean J Physiol Pharmacol 2024;28:335-344
© Korean J Physiol Pharmacol