Fig. 2.

Effects of the nonselective agonist 5′-N-ethylcarboxamido adenosine (NECA) on cardiac contractility (A) and coronary flow (B). Constant pressure-perfused and paced hearts were treated with increasing concentrations (100, 500, and 1,000 nM) of NECA. Baseline contractility was measured before drug infusion, and all data are expressed as percent baseline values. Washout measurements were taken 10 min after the discontinuation of treatment with the highest concentration of NECA. Data are means ± SE; n ≥ 5 experiments/group. *P < 0.05 vs. baseline values.