Influence of atrial natriuretic peptide, brain natriuretic peptide and urodilatin on the histamine-induced bronchoconstriction in the conscious guinea pig.

The influence of human atrial natriuretic peptide (ANP) and of two related peptides, human brain natriuretic peptide (BNP) and urodilatin (URO) on the bronchoconstriction induced by inhalation of histamine in conscious, non-anaesthetized guinea pigs was tested.Changes in lung function were registered using two independent methods, one operating in a closed body-plethysmographic system, the other in an open system based on the time lag of air flow curves. The peptides were infused (0.25 ml/min) into the jugular vein for a period from 10 min before until 15 min after the histamine inhalation.ANP displayed virtually no effect on the bronchoconstriction. URO showed some inibition at 1280ng kg(-1) min(-1), but not at lower doses. BNP (640ng kg(-1) min(-1)) inhibited the bronchoconstriction markedly for the total registration period.It can be concluded from these results that BNP exerts bronchoprotective effects in the conscious guinea pig, which are superior to those of ANP or URO.