title: Expression and effect of Caspase-3 in neurons after tractive spinal cord injury in rats.
abstract: OBJECTIVE
  To investigate Caspase-3 expression and its role in neuronal apoptosis.
  
  
  METHODS
  The T13-L2 spinal cord of rats was injured by traction after the amplitude of P1-N1 wave, monitored by a cortical somatosensory evoked potential (CSEP) monitor, decreased to seventy percent of that before operation. Then rats were killed in 6 h, 1 d, 4 d, 7 d, 14 d and 21 d respectively after operation. Flow cytometer terminal deoxynucleotldyl transferease-mediated biotinylated deoxynuridine triphosphate nick end labeling (TUNEL), Caspase-3 activity assay and immunohistochemical method were applied to investigate Caspase-3 expression in the spinal cord tissue and to study neuronal apoptosis in rats.
  
  
  RESULTS
  After spinal cord injury, apoptotic cells detected by flow cytometry and TUNEL-positive cells were significantly more, and positive immunohistochemical staining of Caspase-3 and Caspase-3 activity were significantly higher in Group injury than in Groups control and laminectomy, respectively (P > 0.05, P > 0.01). Similar trend of changes was noticed in apoptotic cells, TUNEL-positive cells and positive immunohistochemical staining of Caspase-3, all of which reached their respective peak 7 days after operation. Caspase-3 activity reached its peak, however, 4 days postoperatively.
  
  
  CONCLUSIONS
  Increased expression and activity of Caspase-3 protein in neurons after tractive spinal cord injury is the biochemical signal of early spinal cell apoptosis. It is of great significance for understanding the mechanism of spinal cord injury.
authors.affiliation: Department of Orthorpaedic Surgery, Southwestern Hospital, Third Military Medical University, Chongqing, China. leilei_0452@sina.com
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.forename: Fu-xing
authors.initials: FX
authors.lastname: Pei
authors.forename: Kang-lai
authors.initials: KL
authors.lastname: Tang
authors.forename: Jian-zhong
authors.initials: JZ
authors.lastname: Xu
authors.forename: Qi-hong
authors.initials: QH
authors.lastname: Li
mesh_terms: D000818:Animals; D017209:Apoptosis; D053148:Caspase 3; D020169:Caspases / Q000032:analysis* / Q000502:physiology; D005434:Flow Cytometry; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D051381:Rats; D017207:Rats, Sprague-Dawley; D013119:Spinal Cord Injuries / Q000201:enzymology* / Q000473:pathology
chemical_list: C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases