title: [The relationship between hypoxia-inducible factor-1α expression and apoptosis in early brain injury after subarachnoid hemorrhage].
abstract: To investigate the association of hypoxia-inducible factor-1α (HIF-1α) expression and apoptosis in the cerebral cortex following subarachnoid hemorrhage (SAH).
  
  
  
  Subarachnoid hemorrhage was induced by modified monofilament puncture method in rats. Thirty-five adult male Sprague-Dawley rats were randomly assigned to five groups: sham-operated group, SAH 6 h, SAH 12 h, SAH 24 h and SAH 72 h groups. HIF-1α expression was assessed by immunofluorescence staining. TdT-mediated dUTP-biotin nick end-labeling (TUNEL) technique was adopted to detect apoptotic cells. Double immunolabeling was used to identify cell types with positive HIF-1α expression.
  
  
  
  The expression of HIF-1α was increased at 6 h (4.65%±1.01%), peaked at 24 h (18.55%±4.23%), and decreased at 72 h (6.31%±1.15%) after SAH (P<0.05). TUNEL-positive cells were up-regulated in the brain at 6 h (7.09%±2.34%), peaked at 24 h (25.54%±7.36%), and down-regulated at 72 h (14.11%±3.03%) after SAH (P<0.05). A significant positive correlation was noted between HIF-1α positive rates and TUNEL positive rates following SAH (r=0.738, P<0.05). Double immunolabeling indicated that HIF-1α was expressed predominantly in neurons and some nuclei with positive HIF-1α were co-stained with TUNEL.
  
  
  
  The data indicate that HIF-1α might participate in the pathological progression of early brain injury after SAH.
authors.affiliation: Department of Neurosurgery, Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou 310009,China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Hu
authors.affiliation: Department of Neurosurgery, Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou 310009,China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Wu
authors.affiliation: Department of Neurosurgery, Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou 310009,China.
authors.forename: Jing-yin
authors.initials: JY
authors.lastname: Chen
authors.affiliation: Department of Neurosurgery, Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou 310009,China.
authors.forename: Feng
authors.initials: F
authors.lastname: Yan
authors.affiliation: Department of Neurosurgery, Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou 310009,China.
authors.forename: Jian-ru
authors.initials: JR
authors.lastname: Li
authors.affiliation: Department of Neurosurgery, Second Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou 310009,China.
authors.forename: Gao
authors.initials: G
authors.lastname: Chen
mesh_terms: D000818:Animals; D017209:Apoptosis; D001921:Brain / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013345:Subarachnoid Hemorrhage / Q000378:metabolism* / Q000473:pathology
chemical_list: C497444:Hif1a protein, rat; D051795:Hypoxia-Inducible Factor 1, alpha Subunit