[Effect of methylprednisolone on neurological behavior and the BDNF and NMDA receptor expression after traumatic spinal cord injury in rats].
OBJECTIVE
To study the effect of methylprednisolone on spinal cord injury rats' neural behavior and the expression of brain derived neurotrophic factor (BDNF) and N-methyl-D-aspartic acid (NMDA).


METHODS
To establish rat model of spinal cord injury (SCI), the rats were randomly divided into sham operation group, SCI group and methylprednisolone group (n = 16 in each group). Eight rats were used for the behavioral assessment and BDNF measurement,the other eight animals was for the NMDA receptor test in each group. Within 8 h spinal cord contusion, methylprednisolone (50 mg/kg) was injected for methylprednisolone group, then after that the intramuscular injection of methylprednisolone was per day reduction in 10 mg/kg, till 5 days. By using immunohistochemical staining, the distribution of BDNF in the spinal cord and positive cell localization was observed and the number of positive cells were counted. The NMDA receptor affinity (Kd) and maximum binding amount (Bmax) were measured with [3H] MK-801 radioligand method, and the rat hind limb functional was also evaluated with BBB score analysis.


RESULTS
Both the number of BDNF positive cells and the BBB score in methylprednisolone group was significant higher than that of SCI group; While increased receptor affinity (Kd) and decreased Bmax for NMDA receptor in methylprednisolone group was seen less than in SCI group (P < 0.05).


CONCLUSIONS
Methylprednisolone can improve the function of rat hind limb, increase BDNF level and decreased NMDA receptor expression after spinal cord injury.
Department of Bone Injury, Yuxi Municipal Hospital of Traditional Chinese Medicine, Yuxi 653100, China.
Jun
J
Yang
Zheng-Guang
ZG
Xu
Rong
R
Rong
Zhi-Ping
ZP
Lü
Yan-Hua
YH
Sun
Ya
Y
Zhao
Xiao-Song
XS
Li
Jiang-Hua
JH
Liu
Qi-Qin
QQ
Dan
Nan
N
Zhao
D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008775:Methylprednisolone / Q000627:therapeutic use*; D009474:Neurons / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000378:metabolism*; D020127:Recovery of Function / Q000187:drug effects*; D013119:Spinal Cord Injuries / Q000188:drug therapy* / Q000378:metabolism
D019208:Brain-Derived Neurotrophic Factor; D012333:RNA, Messenger; D016194:Receptors, N-Methyl-D-Aspartate; D008775:Methylprednisolone