Induction of glial cell line-derived neurotrophic factor receptor proteinsin cerebral cortex and striatum after permanent middle cerebral artery occlusion in rats

In an attempt to elucidate whether glial cell line-derived neurotrophic fac tor (GDNF) receptors are induced after ischemic brain injury, possible expr ession of immunoreactive GDNF receptor-alpha 1 (GFR alpha-1) and c-ret (RET ) was examined at 3, 8, or 24 h after permanent middle cerebral artery occl usion (MCAO) in rats. Immunohistochemical study showed that both GFR alpha- 1 and RET staining cells which were not detected in sham control brain, wer e present in the ipsilateral cortex and caudate at 3 to 8 h after permanent MCAO, and then decreased but remained to some extent at 24 h. Positive cel ls for both GDNF receptors were predominantly in cortical neurons of ischem ic penumbral area. Western blot analysis confirmed the induction of those r eceptors after permanent MCAO. This rapid induction of GFR alpha-1 and RET, which correlates with the similar induction of GDNF under these conditions , may play a role in the early response to ischemic brain injury. (C) 1999 Elsevier Science B.V. All rights reserved.