Fig. 3.

In vivo normalized coronary blood flow (CBF) and vascular conductance responses to large-conductance Ca²⁺-activated K⁺ (BK_Ca) channel α-subunit activation in nonsham sedentary control (CON), aortic-banded heart failure sedentary (HF), and aortic-banded heart failure interval exercise-trained (HF-IT) animals. A: CBF response [relative to left ventricle (LV) weight] following BK_Ca channel α-subunit activation by NS-1619 is dependent on group (repeated-measures ANOVA, P < 0.05). B: exercise training prevents decreased BK_Ca channel-mediated increases in CBF observed in HF animals, measured as the difference (∆) in CBF following infusion of NS-1619 minus Baseline (1-way ANOVA, P < 0.05). C: NS-1619-induced increases in CBF are attenuated by pretreatment with penitrem A (Pen A) [P = not significant (NS)]. D: increased coronary vascular conductance (CVC; relative to LV weight) following BK_Ca channel α-subunit activation by NS-1619 is dependent on group (repeated-measures ANOVA, P < 0.05). E: again, exercise training prevents decreased BK_Ca channel-mediated vasodilatory capacity observed in HF animals, measured as the difference in CVC following infusion of NS-1619 minus Baseline (1-way ANOVA, P < 0.05). F: NS-1619-induced increases in CVC are attenuated by pretreatment with Pen A (P = NS). §Interaction effect: Group × Dose (P < 0.05); *post hoc vs. CON (P < 0.05), †post hoc vs. HF-IT (P < 0.05); #post hoc vs. CON (P < 0.10); ‡post hoc HF vs. HF-IT (P < 0.10). n = 5, 6, and 6 for CON, HF, and HF-IT, respectively.