Role of spinal cholecystokinin in neuropathic pain after spinal cord hemisection in rats.
In the present study we determined whether spinal cholecystokinin (CCK) or the cholecystokinin receptor is involved in below-level neuropathic pain of spinal cord injury (SCI). The effect of the CCK(B) receptor antagonist, CI-988 on mechanical allodynia and the expression level of CCK and CCK(B) receptor were investigated. Spinal hemisection was done at the T13 level in rats under enflurane anesthesia. CI-988 was administered intraperitoneally and intrathecally and behavioral tests were conducted. After systemic injection, mechanical allodynia was reduced by higher doses of CI-988 (10 and 20mg/kg). Intrathecal CI-988 (100, 200 and 500 microg) dose-dependently increased the paw withdrawal threshold in both paws. Following spinal hemisection, CCK mRNA expression increased on the ipsilateral side at the spinal segments caudal to the injury and both sides of the spinal L4-5 segments without any significant changes in CCK(B) receptor mRNA levels. These results suggest that up-regulation of spinal CCK may contribute to maintenance of mechanical allodynia following SCI and that clinical application of CI-988 or similar drugs may be useful therapeutic agents for management of central neuropathic pain.
Kim
Junesun
J
Department of Physical Therapy, Korea University College of Health Science, Seoul, Republic of Korea.
Kim
Jung Hoon
JH
Kim
Youngkyung
Y
Cho
Hwi-young
HY
Hong
Seung Kil
SK
Yoon
Young Wook
YW
D000818:Animals; D002766:Cholecystokinin / Q000378:metabolism*; D007211:Indoles / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D008536:Meglumine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D010146:Pain / Q000378:metabolism* / Q000503:physiopathology; D010147:Pain Measurement; D010812:Physical Stimulation; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D043887:Receptor, Cholecystokinin B / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D013116:Spinal Cord / Q000378:metabolism*; D013119:Spinal Cord Injuries / Q000503:physiopathology*; D013909:Thorax
D007211:Indoles; D012333:RNA, Messenger; D043887:Receptor, Cholecystokinin B; C065599:PD 134308; D008536:Meglumine; D002766:Cholecystokinin