Figure 3.

Concentration dependence of amiloride and its analogs for A, increase of [³H]ZM‐241,385 dissociation and B displacement of [³H]ZM‐241,385 after reaching binding equilibrium at adenosine A_2A receptors. In A, [³H]ZM‐241,385 binding was allowed to first reach equilibrium at the receptor before its dissociation was induced by addition of an excess of antagonist, in the absence and presence of increasing concentrations of amiloride (analog). The results are expressed as a ratio between the binding of [³H]ZM‐241,385 after 120 minutes in the presence (“B”) and in the absence (B_control) of amiloride (analog). Reproduced with permission from Gao and IJzerman.25 HMA, 5‐(N,N‐hexamethylene)amiloride; MBA, 5‐(N‐methyl‐N‐butyl)amiloride; MGCMA, 5‐(N‐methyl‐N‐guanidinocarbonyl‐methyl)amiloride