Release of vasoactive substances from guinea pig isolated lungs perfused via the trachea.

These findings suggest that a given stimulus, when delivered via the pulmonary circulation of a guinea pig isolated lung, does not reach a population of cells that participate in the anaphylactic response. It is likely that the endothelium in the guinea pig isolated lung acts as a barrier to stimuli coming from the circulation. This may have important therapeutic implications, particularly in regards to the respective efficacy of pharmacologic agents administered systemically or by inhalation in patients with lung injury.