['The aim of this study was to determine the effect of corticosteroids on the increase in airway microvascular permeability (MVP) and airway resistance induced by N-formylmethionine leucyl-phenylalanine in the rabbit.', 'After pretreatment with methylprednisolone (for 1 day or 1 week) rabbits were nebulized with N-formylmethionine leucyl-phenylalanine and MVP was assessed using the Evans blue dye technique (on the trachea, bronchi and bronchioles), while airway resistance was measured using a volume displacement plethysmograph.', 'There were no significant differences in airway resistance between the steroid treated group and the control group for either steroid treatment regime. The degree of extravasation of Evans blue dye was significantly inhibited in the bronchioles after both the 1-day and 1-week treatment with methylprednisolone. There were no significant differences in MVP in the trachea or bronchi between the treated groups and the control groups.'] Does methylprednisolone reduce airway microvascular permeability but not airway resistance induced by N-formylmethionine leucyl-phenylalanine in the rabbit?