Representative whole-cell currents recorded from an isolated cardiomyocyte from either a wild-type (WT) C57B/6 (A), Adora1−/− (B), or Adora3−/− (C) mouse after application of CP-532,903 (1 μM) with corresponding current-voltage relationships of the CP-532,903-elicited current obtained by digital subtraction. D. Summary (n=5–7; means ± SEM) of the effects of CP-532,903 on IKATP showing dependence on expression of the A3 but not the A1AR. Current density was determined at the 0 and +40 mV test pulses from a −40 mV holding potential. All recordings were obtained as described in METHODS in the presence of ZM241385 (100 nM) and PSB603 (100 nM) to block A2A and A2BARs. *P<0.05 vs WT.