Effect of intravenous atrial natriuretic peptide on gas exchange in humans

The aim of this work was to establish whether a physiological increase in atrial natriuretic peptide (ANP) plasma levels affects pulmonary gas exchange in humans. Ten volunteers received an infusion of either ANP (4 pmol.kg-1.min-1) or physiological saline, for 60 min. Baseline measures of the alveolar-arterial PO2 difference and of the physiological dead space were within normal limits and remained stable during and after the infusion of ANP or saline, although plasma ANP and cGMP rose significantly (p < 0.01) (mean +/- SEM: ANP: 13.4 +/- 3.9 to 56.0 +/- 10.4 pmol/l; cyclic GMP: 3.8 +/- 0.3 to 17.0 +/- 3.8 nmol/l). We conclude that a physiological increase in plasma ANP does not affect pulmonary gas exchange significantly in humans.