at the striatal a-2 receptor labeled with [ 3h ] 5'-n-ethylcarboxamidoadenosine in the presence of a low concentration of cyclopentyladenosine to block a-1 receptors labeled by this nonselective adenosine agonist , cgs 15943a had an ic50 value of 3 nm , indicating that the compound had some degree of selectivity for the a-2 receptor .
C0050789
5
C0001443
adenosine