Neuroprotective effect of tacrolimus (FK506) on ischemic brain damage following permanent focal cerebral ischemia in the rat.
We investigated the neuroprotective effect of tacrolimus (FK506) on the ischemic cell death with respect to cytochrome c translocation and DNA fragmentation, which are pivotal events in the necrotic and apoptotic signaling pathway, using permanent focal cerebral ischemia in rats. Immunohistochemically, cytochrome c was observed in the cytoplasm as early as 1 h after middle cerebral artery (MCA) occlusion in the infarcted hemisphere. Cytosolic release of cytochrome c after MCA occlusion was also confirmed by Western blot analysis and enzyme immunoassay. Terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) showed DNA fragmentation evolving in the ipsilateral cortex and the caudate putamen after 3 and 6 h, respectively, following MCA occlusion. Tacrolimus (1 mg/kg, i.v.), administered immediately after MCA occlusion, significantly attenuated the release of cytochrome c in the ischemic region, the number of TUNEL-positive cells in the ischemic penumbra zone, and the size of cortical ischemic lesions. This study demonstrated that tacrolimus ameliorated the accumulation of cytochrome c in the cytosol and the increase of TUNEL-positive cells induced by cerebral ischemia, indicating that the neuroprotective action of tacrolimus on ischemic brain injury caused by permanent focal cerebral ischemia could partially be attributed to the attenuation of the activation of the apoptotic execution machinery.
Noto
Takahisa
T
Medicinal Biology Research Laboratories, Fujisawa Pharmaceutical Co., Ltd., 2-1-6, Kashima, Yodogawa, Osaka, 532-8514, Japan.
Ishiye
Masayuki
M
Furuich
Yasuhisa
Y
Keida
Yuriko
Y
Katsuta
Kiyotaka
K
Moriguchi
Akira
A
Matsuoka
Nobuya
N
Aramori
Ichiro
I
Goto
Toshio
T
Yanagihara
Takehiko
T
D000818:Animals; D002545:Brain Ischemia / Q000188:drug therapy / Q000473:pathology; D002544:Cerebral Infarction / Q000188:drug therapy / Q000473:pathology; D045304:Cytochromes c / Q000378:metabolism; D053938:DNA Fragmentation; D007166:Immunosuppressive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D020287:In Situ Nick-End Labeling; D020244:Infarction, Middle Cerebral Artery / Q000188:drug therapy / Q000473:pathology; D008297:Male; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016559:Tacrolimus / Q000494:pharmacology / Q000627:therapeutic use*
D007166:Immunosuppressive Agents; D018696:Neuroprotective Agents; D045304:Cytochromes c; D016559:Tacrolimus