Figure 4.

Interaction between NOS1 inhibition and APD in affecting intracellular Ca²⁺. Cytosolic Ca²⁺ was measured under AP clamp with long and short APs in the presence of ISO 1 nM; long-short-long sequences were applied within each myocyte. (A) AP waveforms (top) and examples of the corresponding Ca²⁺ transients (bottom) recorded in CTRL. (B) Effect of APD on Ca_D (left) and Ca_T amplitude (right) in CTRL. (C) Half-time of Ca_T-decay in CTRL and during NOS1 inhibition. (D) Effect of APD on Ca_D and Ca_T amplitude during NOS1 inhibition. Sample sizes: CTRL n = 10/4 and SMCT n = 9/3 for B; CTRL n = 29/10 and SMTC n = 34/9 for C; CTRL n = 10/4 and SMCT n = 9/3 for D. ^#P < 0.05 vs. long AP. *P < 0.05 vs. CTRL from the paired Student’s t-test and two-way ANOVA for repeated measurements.