Figure 3.

Inhibition of TRPC3 channels contributes to H-R-induced suppression of IK_Ca and SK_Ca channel activity in PCAECs. Representative traces and current-voltage relationship of whole-cell K⁺ current in PCAECs from different treatment groups before and after bradykinin (BK) stimulation with further application of the IK_Ca channel blocker TRAM-34 and the SK_Ca blocker apamin (a). In H-R group, cells were exposed to 60-min hypoxia and 30-min reoxygenation before patch-clamp recording. *p < 0.05, **p < 0.01, BK vs. basal; ^#p < 0.05, ^##p < 0.01, BK + TRAM-34 vs. BK; ^{^}p < 0.05, ^{^^}p < 0.01, BK + TRAM-34 + Apamin vs. BK + TRAM-34. Pre-treatment of PCAECs with the selective TRPC3 channel blocker Pyr3 significantly inhibited BK-induced IK_Ca and SK_Ca channel currents under both normoxic and H-R conditions (b). Pyr3 exhibited less inhibition on both components of IK_Ca and SK_Ca induced by BK when compared with the cells without H-R exposure (c). *p < 0.05, **p < 0.01, one-way ANOVA and Scheffe post-hoc test (a and b) and unpaired t test (c). n = 5 in each group. N indicates the number of independent experiments, each obtained from cell isolates of different hearts.