[Association of immunization and thermal latencies in rats with chronic constriction injury].
OBJECTIVE
To observe the change of thermal latencies, spinal cord morphology and quantity of microglia following the treatment of lipopolysaccharide (LPS) or cyclosporin A (CsA) in rats with established neuropathic pain through chronic constriction injury (CCI).


METHODS
A total of 36 male SD rats with CCI of sciatic nerve were randomly divided into LPS group, CsA group and NS group, and injected with LPS (1 mg/kg), CsA (6 mg/kg), and NS (2 mL) per day respectively since the 3rd day post operation. The thermal latencies and mechanical thresholds of the rats were measured preoperatively and on the 3rd, 5th, 7th, 10th, 13th and 14th day post operation. The rats were sacrificed on the 14th day and the L4 of spinal cords were harvested for CD11b IHC examination of microglia.


RESULTS
The thermal latencies went down steadily in rats treated with LPS, but went up in rats treated with CsA since the 3rd day after nerve injury. More active microglia were found in the white and grey matter of the spinal cord L4 in rats treated with LPS and NS than in rats treated with CsA. The majority of microglia were inactive in rats treated with CsA.


CONCLUSIONS
Immunomodulator might affect the thermal latencies of CCI rat model, perhaps through microglia in the central nerve system.
Quan
Li
L
Department of Histology and Embryology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China.
Zheng
Xiang
X
Zhou
Xue
X
Zuo
Yun-Xia
YX
Zhang
Wei
W
D000818:Animals; D002908:Chronic Disease; D003251:Constriction, Pathologic / Q000150:complications; D016572:Cyclosporine / Q000494:pharmacology / Q000627:therapeutic use; D007155:Immunologic Factors / Q000494:pharmacology / Q000627:therapeutic use*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D017628:Microglia / Q000473:pathology / Q000502:physiology; D009437:Neuralgia / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D017288:Pain Threshold / Q000187:drug effects*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000473:pathology*; D020886:Somatosensory Disorders / Q000188:drug therapy / Q000209:etiology; D013116:Spinal Cord / Q000473:pathology
D007155:Immunologic Factors; D008070:Lipopolysaccharides; D016572:Cyclosporine