[Effect of inhaled fluticasone on lung inflammation administered during and after guinea pig sensitization]

The effect of an inhaled corticosteroid, fluticasone propionate (FP) lung inflammation of sensitized guinea pig was examined.

Four groups of guinea pigs (n=8) were sensitized (S) with ovalbumin (OA). Control group was given similar solutions without OA. One S group was treated with inhaled 250 microg inhaled FP twice/day during, other group after sensitization for 18 days and two groups were treated with placebo, one during, and the other after sensitization. One day after the last treatment, tracheal responses of all animal groups to methacholine and OA were examined. Total and differential white blood cell (WBC) counts of lung lavage and lung pathology were also examined.

Tracheal responsiveness to both methacholine and OA and WBC of both placebo groups were significantly higher than those of control group (P<0.001 for all cases). The lungs of placebo groups showed variable pathological changes (non significant to P<0.001) compared to control group. Tracheal responsiveness in two treated groups with FP to both methacholine and OA were significantly decreased compared to placebo groups (P<0.01 to P<0.001). Treatment with FP leads to improvement in total (P<0.001) and differential WBC counts (non significant to P<0.001) as well as mucosal detachment (P<0.001), but not other pathological changes.

These results showed a protective effect of FP on tracheal responsiveness and lung inflammation. In addition, this study showed that treatment with inhaled fluticasone propionate, during sensitization (development of inflammation and pathological changes) was more effective than after sensitization (establishment of inflammation and pathological changes).