Evidence indicates that the
adenosine A2A receptor subtype is of critical importance in
stroke. In previous studies, in the model of permanent
middle cerebral artery occlusion (pMCAo), the
adenosine A2A receptor antagonist,
SCH58261, administered soon after
ischemia, proved protective against excessive
glutamate outflow in the first 4 h after
ischemia and against neurological deficit and tissue damage evaluated 24 h after pMCAo. In the present work, we investigated if
neuroprotective effect of
SCH58261 was maintained 7 days after transient MCAo (tMCAo).
SCH58261 (0.01 mg/kg, i.p.), administered twice/day for 7 days, protected from neurological deficit 1 day after tMCAo, but no more after 5 and 7 days. Two days after tMCAo,
SCH58261 did not reduce blood cell infiltration, evaluated as HIS-48 positive cells, into ischemic striatal and cortical tissue. Moreover, 7 days after tMCAo,
SCH58261 has not protected ischemic areas from damage and has not ameliorated myelin organization into the ischemic striatum. Protection by the A2A receptor antagonist 24 h after
ischemia is attributable to reduced excitotoxicity. Seven days after
ischemia the early protective effect of the A2A receptor antagonist likely has been overwhelmed by a secondary damage due to blood cell infiltration and
neuroinflammation.