Fig. 4.

Adenosine-induced negative chronotropic effects on SAN cells in both CTL and HF are mediated by A1R

(a) Representative SAN action potential in CTL (top) and HF (bottom) exposed to ADO in the presence of A1R antagonist, DPCPX (b) Firing rate reduction, (c) SDD reduction, and (d) MDP reduction from BL compared in presence of ADO+ DPCPX compared to ADO alone. Action potential parameters from Fig. 2 were compared with their respective group (HF or control) + DPCPX via one-way ANOVA. SAN cells were isolated from 4 dogs in each group.