The effect of irradiation and methylprednisolone in spinal cord injured rats.
METHODS
This study investigated the outcome of combined therapy with irradiation and methylprednisolone (MP) after a traumatic spinal cord injury (SCI).


OBJECTIVE
To evaluate the neurologic outcomes as well as the antiapoptotic and anti-inflammatory effects on traumatic SCI in rats after combined therapy.


BACKGROUND
Although irradiation carries the risk of secondary SCI, it has been effective for the regeneration of the axons of nerve cells by reducing gliosis. Thus, to minimize apoptosis and irradiation risks after SCI, this study investigated the effects of steroid injections before irradiation.


METHODS
Thirty-two rats were used for the experimental procedure. After a traumatic SCI, they were divided into 4 groups of 8 rats each: (1) a control group that only had rats with a SCI (Group 1); (2) a group that received MP at 30 minutes, 6 hours and 24 hours, and then received irradiation 2 days after the SCI (Group 2); (3) a group that received MP at 30 minutes, and irradiation 2 days after the SCI (Group 3); and (4) a group that received irradiation 2 days after the traumatic SCI (Group 4).


RESULTS
The degree of recovery using the inclined plane climbing test was greatest in Group 2, followed by Group 3, Group 4, and Group 1. The cavitation lesions, Terminal Deoxynucleotidyl Transferase dUTP Nick End Labeling -positive apoptosis, glial fibrillary acidic protein-positive astrocyte count, and CC-1-positive oligodendrocyte count significantly decreased in the irradiated groups (Groups 2, 3, 4) compared to the control group (Group 1). In particular, they decreased considerably more in the group that received MP 3 times (Group 2) compared to the group that received MP only once (Group 3).


CONCLUSIONS
These results suggest that the combined therapy was effective and might provide synergistic effects for neurologic recovery after a traumatic SCI.
Department of Orthopaedic Surgery, St Paul's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Sung-Jin
SJ
Park
In-Soo
IS
Oh
Jae-Young
JY
Kwon
Kee-Yong
KY
Ha
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D003131:Combined Modality Therapy; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007150:Immunohistochemistry; D008775:Methylprednisolone / Q000627:therapeutic use*; D009043:Motor Activity / Q000187:drug effects / Q000528:radiation effects; D009457:Neuroglia / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects; D009474:Neurons / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects; D018696:Neuroprotective Agents / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D013119:Spinal Cord Injuries / Q000188:drug therapy* / Q000503:physiopathology / Q000532:radiotherapy*; D016896:Treatment Outcome
D005904:Glial Fibrillary Acidic Protein; D018696:Neuroprotective Agents; D008775:Methylprednisolone