[Changes in alpha2-adrenergic receptors gene expression after high-level spinal cord injury in Wistar rats].
OBJECTIVE
To evaluate the change in alpha(2)-adrenergic receptors (alpha(2)-ARs) gene expression after high-level injury of the spinal cord (SCI), aiming as developing a more effective perioperative anesthetic management for high-level SCI patients.


METHODS
Adult male Wistar rats were anesthetized and severe spinal crush injury at T4 was produced using modified Allens device. The expression of alpha(2)-ARs mRNA at different levels of spinal cord in normal control rats (C), injured segment (I), above (A) and below (B) the site of injured segment, were measured by reverse transcription-polymerase chain reaction (RT-PCR) 1 day, 3 days, 1 week, 2 weeks, 3 weeks and 4 weeks, respectively after SCI.


RESULTS
Compared with group C (sham group), in group A the expression of alpha(2)-ARs mRNA decreased 1 day after SCI (P<0.05) and dropped to the nadir 2 weeks later (P<0.01), but the expression was restored to the normal level 4 weeks later. In group I the lowering of alpha(2)-ARs mRNA expression occurred immediately after SCI and down to the lowest value 1 week later (P<0.01), and did not recover to normal level 4 weeks later (P<0.05). In group B downregulation of alpha(2)-ARs mRNA expression was detected 1 day after SCI (P<0.05), but it was upregulated 1 week later reaching the normal level, which was maintained for 4 weeks.


CONCLUSIONS
In a chronic SCI rat model, alpha(2)-ARs gene expression is downregulated in the injured segment, but returns to the normal level above and below the injured segment. The changes in alpha(2)-ARs may be a pivotal factor contributing to a series of abnormal responses after high-level SCI.
He
Xing-ying
XY
Department of Anesthesiology, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, China.
Shi
Xue-yin
XY
Yuan
Hong-bin
HB
Xu
Hai-tao
HT
Wang
Ya-hua
YH
D000818:Animals; D004195:Disease Models, Animal; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D018341:Receptors, Adrenergic, alpha-2 / Q000235:genetics / Q000378:metabolism*; D013116:Spinal Cord / Q000378:metabolism*; D013119:Spinal Cord Injuries / Q000378:metabolism*
D012333:RNA, Messenger; D018341:Receptors, Adrenergic, alpha-2