ADENOSINE MODULATES ENDOTHELIN-INDUCED BRONCHOCONSTRICTION IN GUINEA-PIG AIRWAY

The present study was designed to determine whether endogenous and exo genous adenosine modulates endothelin (ET)-induced bronchoconstriction . Exogenous adenosine enhances ET-induced bronchoconstriction. Followi ng pretreatment with adenosine deaminase and theophylline to eliminate or antagonize endogenous adenosine. ET-1-induced bronchoconstriction was significantly attenuated, but not that of ET-3. In conclusion, thi s is the first report of an enhancement of ET-induced bronchoconstrict ion of guinea pig airways by endogenous and exogenous adenosine. Our f indings may be useful in designing specific adenosine receptor antagon ists as therapeutic agents in the management of bronchial asthma.