Objective      To investigate the effect of dexmedetomidine on spinal cord ischemia-reperfusion injury in rats

and explore possible mechanism.      Methods      A random number table method was used to divide 96 adult SD rats into 4 groups (n=24):sham-operation group (S)

ischemia-reperfusion group (IR)

dexmedetomidine treatment group (DEX)

anddexmedetomidine and yohimbine combination treatment group (DY). Each group wa

s further divided into 4 subgroups (n=6) according to time points (12

24

48 and 72 h) after ischemia-reperfusion injury. After the spinal cord ischemia-reperfusion injury model was established with an improved Zivin method

the motion function of the hind limbs was evaluated by BBB scale

andthe pathological changes in L

4

-L

6

spinal cords were observed by HE staining. The expression of Bcl-2 and Bax was examined by immunohistochemical staining

and the expression of Caspase 3 was detected by Western blotting. Meanwhile

the apoptotic rate of spinal cord cells was calculated by TUNEL assay.      Results      Compared with group IR

group DEX and group DY showed higher motion function scores

less pathological injury

lower expression of Bax and Caspase 3

higher expression of Bcl-2

and lower apoptotic rate (P0.05). Compared with group DY

group DEX had better outcomes in the above indexes.      Conclusion      Dexmedetomidine has neuroprotective effect on spinal cord ischemia-reperfusion injury through activation of α

2

-adrenoreceptors

phosphorylation of FAK

up-regulation of Bcl-2

and down-regulation of Bax and Caspase 3.