A: reproducibility of the effects of Cl-IB-MECA on coronary flow of isolated mouse hearts. Cl-IB-MECA (1 μM) was infused for 10 min, followed by 30-min drug-free wash before the next exposure. Bars represent means ± SE of three hearts in a paired manner. B: influence of selective blockade of adenosine A2A receptor with 7-(2-phenylethyl)-5-amino-2-(2-furyl)-pyrazolo-[4,3-e]-1,2,4-triazolo-[1,5-c]pyrimidine (SCH-58261) on Cl-IB-MECA-induced increases in coronary flow in A3KO hearts. Control responses to Cl-IB-MECA (1 μM) were first determined in the absence of SCH-58261. After 30-min washout, hearts were pretreated with SCH-58261 (100 nM) for 10 min before second exposure to Cl-IB-MECA. Bars represent means ± SE of 5 experiments from different hearts in a paired manner. Vehicle control experiments were done in four hearts. *P < 0.05 vs. vehicle control; #P < 0.05 vs. respective control.