In vivo induction of the growth associated protein GAP43/B-50 in rat astrocytes following transient middle cerebral artery occlusion.

Immunohistochemistry was used to investigate the induction of growth-associated protein GAP43/B-50 in the astrocytes of rat cerebrum in vivo following ischemic injury produced by 30 min of transient middle cerebral artery occlusion. Three days after operation, GAP43 immunoreactivity first appeared in some astrocytic populations surrounding the infarcted lesion. Induction of GAP43 in those astrocytes persisted for up to 14 days and disappeared at 30 days postoperation. Double-immunofluorescence staining confirmed that the GAP43-immunoreactive astrocytes examined were all positive for glial fibrillary acidic protein. Our present data suggest that certain astrocytes could be induced to synthesize GAP43 in vivo in response to an ischemic insult in adult rats.