title: Neuroprotective effect of diazoxide on brain injury induced by cerebral ischemia/reperfusion during deep hypothermia.
abstract: OBJECTIVE
  The purpose of this study was to determine the effects of diazoxide on apoptosis and the relative mechanisms in a model of brain injury induced by cerebral ischemia/reperfusion (I/R) during deep hypothermia.
  
  
  METHODS
  Three-week-old Sprague-Dawley male rats were randomly and equitably divided into sham-operated group, placebo-treated group and diazoxide-treated group respectively. Specific examination of the regional cerebral blood flow (rCBF) was measured in the three groups continuously during the operation by laser Doppler flowmetry. Terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) was showed DNA fragmentation. The mRNA expressions of cytochrome c and full-length caspase-3 were determined by RT-PCR, while the protein expressions of cytochrome c and cleaved caspase-3 were determined by immunohistochemistry at 1 h, 6 h, 24 h, 72 h and 7 days after I/R, respectively. Cytosolic release of cytochrome c at 24 h after I/R was also confirmed by Western blot.
  
  
  RESULTS
  rCBF was significantly decreased in both of placebo-treated and diazoxide-treated group just after ischemia in the time interval 0-5 min, and had no obvious changes in all the time intervals during the operation. Diazoxide preconditioning significantly decreased the percentage of TUNEL-positive staining cells. The mRNA expressions of cytochrome c and full-length caspase-3 in diazoxide-treated group were significantly decreased. In addition, diazoxide provided a significant reduction in the protein expressions of cytochrome c and cleaved caspase-3.
  
  
  CONCLUSIONS
  These results suggested that the neuroprotective effects of diazoxide against cerebral I/R injury during deep hypothermia correlated with the reduction of DNA fragmentation, prevention of mitochondrial cytochrome c release and inhibition of caspase-3 activation.
authors: Department of Cardiothoracic Surgery, Children's Hospital Nanjing, Nanjing Medical, University, Nanjing, 210008, China.
authors: Xiaomin
authors: X
authors: He
authors: Xuming
authors: X
authors: Mo
authors: Haitao
authors: H
authors: Gu
authors: Feng
authors: F
authors: Chen
authors: Qun
authors: Q
authors: Gu
authors: Wei
authors: W
authors: Peng
authors: Jirong
authors: J
authors: Qi
authors: Li
authors: L
authors: Shen
authors: Jian
authors: J
authors: Sun
authors: Rufang
authors: R
authors: Zhang
authors: Yin
authors: Y
authors: Kj
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001930:Brain Injuries / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control*; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D002560:Cerebrovascular Circulation / Q000502:physiology; D045304:Cytochromes c / Q000235:genetics / Q000378:metabolism; D003981:Diazoxide / Q000627:therapeutic use*; D004195:Disease Models, Animal; D005786:Gene Expression Regulation; D007036:Hypothermia, Induced / Q000009:adverse effects*; D020287:In Situ Nick-End Labeling / Q000379:methods; D017078:Laser-Doppler Flowmetry / Q000379:methods; D008297:Male; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000628:therapy*; D013997:Time Factors
chemical_list: D018696:Neuroprotective Agents; D045304:Cytochromes c; D053148:Caspase 3; D003981:Diazoxide