Atrial natriuretic peptide and plasma renin activity in patients with stable chronic obstructive pulmonary disease

The relationship between plasma atrial natriuretic peptide (ANP) and plasma renin activity (PRA) was examined in patients with stable chronic obstructive pulmonary disease (COPD, n = 17). The plasma ANP level in patients was approximately twice that in normal subjects. A reciprocal relationship between ANP and PRA was shown in normal subjects; however, this relationship was not observed in COPD. Plasma ANP levels inversely correlated with PaO2, and tended to inversely correlate with angiotensin converting enzyme activity in serum. These results demonstrate that patients with COPD have higher plasma ANP concentration, and that ANP and PRA are not reciprocally related in stable COPD.