Atrial natriuretic peptide release in the rabbit is independent of cardiac nerve activity

1. Changes in plasma atrial natriuretic peptide (ANP) were examined in conscious rabbits in response to a 33% blood volume expansion in intact animals and after blockade of cardiac nerve activity. 2. Blood volume expansion by one-third markedly increased right atrial pressure and resulted in a four-fold increase in plasma ANP. 3. Cardiac nerve blockade with intrapericardial procaine had no effect on resting plasma ANP levels. The ANP responses to volume expansion in the presence of cardiac nerve blockade were similar to those seen in intact animals. 4. Release of ANP from its cardiac stores in response to volume expansion is not influenced by cardiac nerve activity.