[Mechanism of radiculopathy induced by experimentally herniated nucleus pulposus in rats].
OBJECTIVE
To determine the effects of the autologous nucleus pulposus on the pain-related behaviors of hind paws in rats.


METHODS
The nucleus pulposus harvested from autologous coccygeal vertebra was applied beside the unilateral L4 and L5 nerve roots without compression. The mechanical withdrawal threshold of both paws were measured in different times after surgery. And hematoxylin and eosin (HE) staining was applied to observe the changes of nucleus pulposus and nerve roots.


RESULTS
Mechanical sensitivity of the operated side in paws obviously increased after application of autologous nucleus pulposus beside the lumbar nerve roots without compression. And HE staining showed obviously inflammatory changes in the nucleus pulposus and vacuolation in the nerve roots.


CONCLUSIONS
Inflammation resulted from nucleus pulposus may contribute to the development of mechanical hyperalgesia. The results suggest that in addition to mechanical compression, inflammation may be an important factor in the pathogenesis of sciatica.
Tang
Jia-guang
JG
Institute of Orthopedics, 304 Hospital of People's Liberation Army, Beijing 100037, China.
Hou
Shu-xun
SX
Zhang
Wei-jia
WJ
Liang
Hong-ying
HY
D000818:Animals; D004195:Disease Models, Animal; D006930:Hyperalgesia / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D007405:Intervertebral Disc Displacement / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D011843:Radiculopathy / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley