ADENOSINE A(3) RECEPTOR STIMULATION AND CEREBRAL-ISCHEMIA

Chronic treatment with the selective adenosine A(3) receptor agonist N-6-(3-iodobenzyl)adenosine-5'-N-methylcarboxamide (IB-MECA) administered prior to either 10 or 20 min forebrain ischemia in gerbils resulted in improved postischemic cerebral blood circulation, survival, and neuronal preservation. Opposite effects, i.e., impaired postischemic blood flow, enhanced mortality, and extensive neuronal destruction in the hippocampus were seen when IB-MECA was given acutely. Neither adenosine A(1) nor A(2) receptors are involved in these actions. The data indicate that stimulation of adenosine A(3) receptors may play an important role in the development of ischemic damage, and that adenosine A(3) receptors may offer a new target for therapeutic interventions.