Spinal GABA receptors mediate the suppressive effect of electroacupuncture on cold allodynia in rats.
This study was performed to determine whether spinal GABAergic systems mediate the relieving effects of low frequency electroacupuncture (EA) on cold allodynia in a rat tail model of neuropathic pain. For neuropathic surgery, the right superior caudal trunk was resected at the level between the S1 and S2 spinal nerves innervating the tail. Two weeks after the nerve injury, the intrathecal catheter was implanted. Five days after the catheterization, rats were intrathecally injected with gabazine (GABA(A) receptor antagonist, 0.0003, 0.001 or 0.003mug), or saclofen (GABA(B) receptor antagonist, 3, 10 or 30mug). Ten minutes after the injection, EA (2Hz) was applied to the ST36 acupoint for 30min. The cold allodynia was assessed by the tail immersion test (i.e. immersing the tail in cold (4 degrees C) water and measuring the latency of an abrupt tail movement) before and after the EA treatment. EA stimulation at ST36 significantly inhibited the cold allodynia sign, whereas EA at non-acupoint and plain acupuncture at ST36 (without electrical stimulation) did not show antiallodynic effects. Intrathecal administration of gabazine or saclofen blocked the relieving effects of ST36 EA stimulation on cold allodynia. These results suggest that spinal GABA(A) and GABA(B) receptors mediate the suppressive effect of low frequency EA on cold allodynia in the tail neuropathic rats.
Department of East-West Medicine, Graduate School, Kyung Hee University, Seoul 130-701, South Korea.
Jung-Hyun
JH
Park
Jae-Bok
JB
Han
Sun-Kwang
SK
Kim
Jung-Hyuk
JH
Park
Dong-Hyun
DH
Go
Boram
B
Sun
Byung-Il
BI
Min
D000818:Animals; D003080:Cold Temperature / Q000009:adverse effects; D003714:Denervation; D004195:Disease Models, Animal; D015671:Electroacupuncture; D018756:GABA Antagonists; D058787:GABA-A Receptor Antagonists; D058788:GABA-B Receptor Antagonists; D006930:Hyperalgesia / Q000378:metabolism* / Q000503:physiopathology / Q000628:therapy; D015918:Infusion Pumps, Implantable; D007278:Injections, Spinal; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology; D010523:Peripheral Nervous System Diseases / Q000378:metabolism* / Q000503:physiopathology / Q000628:therapy; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D018079:Receptors, GABA / Q000187:drug effects / Q000378:metabolism*; D011963:Receptors, GABA-A / Q000378:metabolism; D018080:Receptors, GABA-B / Q000378:metabolism; D013116:Spinal Cord / Q000378:metabolism* / Q000503:physiopathology; D013127:Spinal Nerves / Q000503:physiopathology / Q000601:surgery; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D018756:GABA Antagonists; D058787:GABA-A Receptor Antagonists; D058788:GABA-B Receptor Antagonists; D018079:Receptors, GABA; D011963:Receptors, GABA-A; D018080:Receptors, GABA-B; D005680:gamma-Aminobutyric Acid