Spinal cord decompression reduces rat neural cell apoptosis secondary to spinal cord injury.
OBJECTIVE
To determine whether spinal cord decompression plays a role in neural cell apoptosis after spinal cord injury.


METHODS
We used an animal model of compressive spinal cord injury with incomplete paraparesis to evaluate neural cell apoptosis after decompression. Apoptosis and cellular damage were assessed by staining with terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate nick-end labelling (TUNEL) and immunostaining for caspase-3, Bcl-2 and Bax.


METHODS
Experiments were conducted in male Sprague-Dawley rats (n=78) weighing 300-400 g. The spinal cord was compressed posteriorly at T10 level using a custom-made screw for 6 h, 24 h or continuously, followed by decompression by removal of the screw. The rats were sacrificed on Day 1 or 3 or in Week 1 or 4 post-decompression. The spinal cord was removed en bloc and examined at lesion site, rostral site and caudal site (7.5 mm away from the lesion).


RESULTS
The numbers of TUNEL-positive cells were significantly lower at the site of decompression on Day 1, and also at the rostral and caudal sites between Day 3 and Week 4 post-decompression, compared with the persistently compressed group. The numbers of cells between Day 1 and Week 4 were immunoreactive to caspase-3 and B-cell lymphoma-2 (Bcl-2)-associated X-protein (Bax), but not to Bcl-2, correlated with those of TUNEL-positive cells.


CONCLUSIONS
Our results suggest that decompression reduces neural cell apoptosis following spinal cord injury.
Xu
Kan
K
Department of Orthopaedic Surgery, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China. xukan@medmail.com.cn
Chen
Qi-xin
QX
Li
Fang-cai
FC
Chen
Wei-shan
WS
Lin
Min
M
Wu
Qiong-hua
QH
D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D019299:Decompression, Surgical; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000473:pathology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013119:Spinal Cord Injuries / Q000473:pathology* / Q000601:surgery*
D019253:Proto-Oncogene Proteins c-bcl-2; D053148:Caspase 3