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 g as exchange in humans. Ten volunteers received an infusion of either A NP (4 pmol.kg(-1).min(-1)) or physiological saline, for 60 min. Baseli ne measures of the alveolar-arterial Po, difference and of the physiol ogical 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.