Inhibition of Adenosine Transport
Propentofylline reinforces adenosine actions by blocking its cellular reuptake via
nucleoside transporters. Adenosine, which is present in the normal brain at concentrations
between 30 and 100 nM, acts as a homeostatic neuromodulator (62,65). Adenosine
is rapidly inactivated by adenosine deaminase and by an eflicient cellular reuptake
system utilizing nucleoside transporters. During brain ischemia, large quantities
of adenosine are formed during ATP catalysis and are subsequently released into the
extracellular space. Inhibitors of adenosine transport into cells (e.g., dipyridamole and