the substituted adenosine derivatives , r-phenylisopropyladenosine ( r-pia ) and 5'- ( n-ethylcarboxamido ) -adenosine ( neca ) , and the adenosine transport inhibitor , 6- [ p-nitrobenzyl ) thio ] -9-beta-d-ribofuranosyl purine , were also active as modulators , but their activity was relatively weak and varied with the stimulus and the tissue .
C0001443
adenosine
C0050789
neca