pit ( 21 mug/ml ) potentiated responses to adenosine , atp and adenine by an unexplained mechanism.4 caffeine ( 25 mug/ml ) partially relaxed the trachea and inhibited spasmolytic responses to both adenosine and atp , but not to adenine , isoprenaline , aminophylline or prostaglandin e ( 2 ) ( pge ( 2 ) ) .5 a number of compounds related to caffeine ( xanthine , hypoxanthine , theophylline and theobromine ) were tested for adenosine antagonist activity .
C0001480
atp
C0001443
adenosine