Coronary hemodynamics and cardiac beating modulate atrial natriuretic factor release from isolated...

The role of coronary hemodynamics and cardiac beating on atrial natriuretic factor (ANF) release was studied in the isolated Langendorff-perfused rat heart. ANF release was measured by radioimmunoassay. When the coronary flow rate was changed, ANF release decreased or increased in a flow-dependent manner. When the perfusion pressure was changed, ANF release also increased or decreased, respectively, with concomitant changes in coronary flow rate. Furthermore, perfusion with 50 mM potassium chloride showed immediate cardiac arrest and a decrease of ANF release to an undetectable level with a significant decrease in coronary flow. However, low but readily detectable amounts of ANF were released when coronary flow rate was maintained. These results may suggest that coronary hemodynamics and cardiac beating could be factors modulating ANF secretion from the atrium.