The influence of epithelium on the responsiveness of XXXX trachea to -adrenergic agonist and antagonist.

@entity3044 @entity565 @entity840 @entity1169
BACKGROUND: There is controversy regarding bronchial responsiveness to b2-agonist drugs in @entity565 . Epithelial shedding in the airways is a pathological feature of @entity565 . Therefore, the present study focused on the effect of epithelial denudation of @entity840 tracheal chains in response to @entity3044 and b-adrenergic receptor blockade. MATERIAL/METHODS: In control (group 1, n=10), epithelium-denuded (group 2, n=10), and epithelium-denuded + epithelial cell (group 3 n=6) we measured the responses of tracheal chains to cumulative concentrations of @entity3044 (I) in the absence and presence of 10 nM @entity1169 , and the value of EC50I was calculated. The @entity1169 blockade (CR-1) was calculated as the ratio of post @entity1169 EC50I to initial EC50I. RESULTS: The tracheal responses to @entity3044 (EC50I) in groups 2 and 3 was significantly higher than in the controls (p<0.05 for both cases), but was not significantly different between the groups 2 and 3. The values of CR-1 in group 2 only was significantly higher than the controls (p<0.001). The mean CR-1 in group 3 was significantly lower than in group 2 (p<0.01). There was significant negative correlation between EC50I and CR-1 in all three groups (p=0.002). CONCLUSIONS: The results of this study indicate increased tracheal response to a b-adrenergic stimulating drug in both groups 1 and 2, and enhancement of b-adrenergic blockade by @entity1169 only in group 1. These results may indicate some of the mechanisms of @entity565 aggravation by b2-antagonist drugs.
