Abstract
The effect of duration of administration of fluticasone propionate and salmeterol on tracheal responsiveness to ovalbumin and total and differential white blood cell in sensitized guinea pig was examined. Six groups of guinea pigs (n=7) were sensitized to ovalbumin. Three groups of them were subjected to inhaled fluticasone propionate and salmeterol, one group during sensitization (A), one group after that (for 18 days, B), and the other one during sensitization but with 18 days delay before measurements (C). Three other groups were treated with placebo in the same manner. The tracheal responsiveness to ovalbumin and total and differential white blood cells of three placebo groups were significantly higher than those of control group (P<0.001 for all cases). Tracheal responsiveness to ovalbumin and total and differential white blood cell in treated groups with fluticasone propionate and salmeterol were significantly decreased compared to those of placebo groups (nonsignificant to P<0.001). The improvement in all variables in treatment groups A and C were more pronounced than group B. The results showed that fluticasone propionate and salmeterol had a prevention effect on tracheal hyperresponsiveness to ovalbumin and lung inflammation which was more pronounced when administered during than after sensitization.