Increased Vascular Permeability in Inflammation

Despite their small size, endothelial gaps have an enormous effect on endothelial permeability (Majno and Palade, 1961 Clough, 1991 Wu and Baldwin, 1992b  

2 Late phase inflammatory Response Unknown Mechanism OF Plasma leakage 

It is uncertain which vessels leak in the late phase response. Although venules are labelled with the tracer Monastral blue in a dog model of allergen-induced late phase response (Ohrui et al., 1992), no vessels are labelled in the late phase response evoked in guinea-pig airways by PAF (O Donnell et al., 1990). It is unclear whether this diflference is due to differences in the animal models or to limitations of the methods used to identify the leaky vessels. One reason for considering that the late phase leak may not be just a longer version of the early response is evidence that prolonged inflammatory stimuli 

The increase in vascular permeability associated with inflammation often is accompanied by the emigration of leukocytes out of the micro vasculature. Neutrophils and eosinophils are found in the airways of guinea-pigs, rabbits, dogs and humans after allergen challenge they are also in the airway mucosa of patients who have died from asthma (Williams et al., 1991). What then is the relationship between vascular permeability and neutrophil migration  

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