An adenosine analogue, 2-chloroadenosine, protects against long term development of ischaemic cell loss in the rat hippocampus

Delayed ischaemic damage was assessed by LIGHT microscopy following 10 min of incomplete forebrain ischaemia and 7 days of reperfusion. Iterative focal injections of 2-chloroadenosine, a stable analogue of adenosine, protect against selective hippocampal CA1 loss (P less than 0.01), when given either immediately before ischaemia and after 4 and 10 h of reperfusion or after 1 min, 4 h and 10 h of reperfusion. Delayed focal injection of 2-chloroadenosine after 10 and 24 h of reperfusion fails to protect against CA1 cell loss. The mechanism of cerebroprotection may involve attenuation of excitatory neurotransmission.