Abstract: AIM: To establish the model of isolated human lung, and to study the effect of CGP-12177 on alveolar fluid clearance (AFC) in isolated human lung and the mechanisms involved.METHODS: The AFC was measured by the concentration of Evansblue-labeled album in the istilled and aspirated solution. Isomolar albumin solution in the presence of 10^-4 mol/L to 10^-7 mol/L CGP-12177 (selective β₃-adrenergic agonists) was injected into the alveolar spaces in isolated human lung, and AFC was measured. 10^-5 mol/L CGP-12177 combined with phentolamine (α receptor antagonist), atenolol (β₁ receptor antagonist), ICI-118551 (β₂ receptor antagonist), SR59230A (β₃ receptor antagonist), sodium channel blockers or Na⁺/K⁺-ATPase blockers were perfused into the alveolar space of isolated human lung.RESULTS: 10^-5 mol/L and 10^-6 mol/L CGP-12177 increased AFC significantly in isolated human lung,but 10^-4 mol/L and 10^-7 mol/L CGP-12177 didn't increase AFC. The AFC-stimulating effect of CGP-12177 was decreased by SR59230A, amiloride and ouabain.CONCLUSION: CGP-12177, a β₃-adrenergic agonist, can increase AFC in isolated human lung by promoting the transport of Na⁺-K⁺-ATPase.

Key words: isolated human lung, adrenergic agonist, lung injury