[Molecular forms of plasma atrial natriuretic peptide (ANP) after three kinds of ANP releasing stimulation]

This study analyzed by high performance gel permeation chromatography (HPGC) molecular forms of atrial natriuretic peptide (ANP) in plasma from anesthetized dogs stimulated by balloon inflation at the main pulmonary artery (Group A, n = 4), right atrial pacing (Group B, n = 4) and low-molecular dextran injection to right atrium (Group C, n = 4). Mean pulmonary arterial (PA) pressure, mean right atrial (RA) pressure, mean arterial pressure, heart rate and ECG were monitored by polygraph system Mean PA pressure in Group A, heart rate in Group B and mean RA pressure in Group C increased significantly by the stimulation (p less than 0.01, p less than 0.001 and p less than 0.05 respectively). Other parameters were not changed significantly in the three groups. There were significant increases in ANP concentration after the three stimulations (Group A: 52.4 +/- 5.4 (SD) pg/ml----86.4 +/- 12.2 (SD) pg/ml, Group B: 43.8 +/- 6.7 (SD) pg/ml----72.0 +/- 14.1 (SD) pg/ml, Group C: 42.7 +/- 8.8 (SD) pg/ml----69.3 +/- 10.0 (SD) pg/ml; each p less than 0.01). Gel filtration profiles showed that the increased form of plasma ANP in the three groups was alpha-ANP. These results suggest that alpha-ANP may be a main molecular form in plasma from dogs stimulated by the stretch of pulmonary arterial wall and right atrial wall, and atrial pacing.