In order to examine the effect of neurotrophin-3 (NT-3) on ischemic brain i
njury, NT-3 was topically applied to brain surface just after 90 min of mid
dle cerebral artery occlusion (MCAO) in rats. NT-3 significantly reduced th
e infarct size at 24 h of reperfusion. Terminal deoxynucleotidyl transferas
e-mediated dUTP-biotin in situ nick labeling (TUNEL) staining and immunohis
tochemical study for caspase-3 and heat shock protein 72 (HSP72) showed tha
t NT-3 treatment decreased the number of cells with DNA fragmentation and c
aspase-3 and HSP72 expressions. These data suggest that NT-3 protects neuro
nal cells from ischemic injury, and it is possibly associated with inhibiti
on of DNA fragmentation. (C) 1999 Elsevier Science B.V. All rights reserved
.