Action of synthetic atrial natriuretic factor on contractility and coronary perfusion in isolated working rat hearts

The effects of atrial natriuretic factor were studied in isolated working rat hearts. Increasing concentrations, from 0.1 to 100 nM, of a synthetic rat-ANF (atrial natriuretic factor) were added to the perfusate. ANF had no effect on heart rate, contraction cycle or coronary resistance in concentrations up to 3 nM. At concentrations above 10 nM, peak dP/dt and oxygen consumption showed a slight dose-dependent increase. The greater decrease in coronary resistance, and the lowering of coronary oxygen extraction, suggest that ANF has a small coronary dilating effect. No arrhythmias were observed at any concentration of ANF.