low doses ( 0.25-5 mu/kg ) of synthetic adenosine receptor agonists potentiated all four of the tested sympathomimetic responses to nicotine , exhibiting the rank order of potency : n-cyclopropylcarboxamidoadenosine greater than 2-chloroadenosine greater than n6-r-phenylisopropyl adenosine greater than n6-s-phenylisopropyladenosine .
C0001443
adenosine
C0031484
phenylisopropyladenosine