Abstract | OBJECTIVE: To observe the effect of electroacupuncture (EA) at different acupoints on the expression of gamma aminobutyric ( GABA) receptor (R) subunit genes in the cervical spinal cord in rats with thyroid regional inflammatory pain so as to analyze its analgesic mechanism for thyroid surgery. METHODS: A total of 50 Wistar rats were randomized into control, model, Futu (LI 18), Hegu (LI 4)-Neiguan (PC 6, LI 4-PC 6), Zusanli (ST 36)-Yanglingquan (GB 34, ST 36-GB 34) groups, with 10 rats in each group. Thyroid regional pain model was established by subcutaneous injection of 2.5% formalin (100 microL). Ten minutes after modeling, EA (2 Hz/15 Hz, 1 mA) was applied to LI 18, LI 4-PC 6 and ST 36-GB 34 for 30 min, respectively. The animals' face-grooming (FG) times in 5 min and thermal pain threshold (paw withdrawal latency, PWL) were recorded. The expression of GABA(A) R, GABA(B) R1, and GABA(B) R2 genes in the cervical 1-3 segments of the spinal cord 80 min after modeling was detected by using reversed transcription-polymerase chain reaction (RT-PCR). Histological changes of the tissues of the thyroid region were observed by using H. E. staining. RESULTS: After subcutaneous injection of formalin, the animals' FG times in 5 min were increased considerably and the thermal pain threshold was decreased obviously in the model group (P < 0.05). Concomitantly, the expression levels of GABA(B) R1, and GABA(B) R2 genes of the cervical spinal cord were upregulated significantly in the model group (P < 0.05), and GABA(A) R expression was increased slightly (P > 0.05). Compared with the model group, the FG times in 5 min in the LI 18 and LI 4-PC 6 groups at 40 min and 70 min after modeling were decreased significantly (P < 0.05), and their thermal pain threshold values were increased markedly (P < 0.05). The expression levels of GABA(B) R1 mRNA, GABA(B) R2 mRNA and GABAA R mRNA were significantly higher in the LI 18 and LI 4-PC 6 groups than in the model group (P < 0.05). The expression level of GABA(B) R1 mRNA of the ST 36-GB 34 group was obviously higher than that of the model group (P < 0.05). The inflammatory cells in the formalin-injected thyroid region were relatively fewer in the LI 18 and LI 4-PC 6 groups than in the model group. CONCLUSION: Both EA of LI 18 and LI 4-PC 6 can significantly suppress formalin-injection induced pain reactions in the thyroid region, which may be closely associated with its effects in upregulating expression levels of cervico-spinal GABA(B) R1 mRNA, GABA(B) R2 mRNA and GABA(A) R mRNA, and reduce regional inflammatory reactions in the thyroid region.
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Authors | Yong-Hui Gao, Shu-Ping Chen, Jun-Ying Wang, Li-Na Qiao, Yan-Jing Han, Dan Lin, Chang-Fu Ji, Qiu-Ling Xu, Jun-Ling Liu |
Journal | Zhen ci yan jiu = Acupuncture research
(Zhen Ci Yan Jiu)
Vol. 37
Issue 2
Pg. 93-8
(Apr 2012)
ISSN: 1000-0607 [Print] China |
PMID | 22764592
(Publication Type: Evaluation Study, Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Receptors, GABA
- Receptors, GABA-B
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Topics |
- Acupuncture Analgesia
(methods)
- Acupuncture Points
- Animals
- Cervical Vertebrae
(metabolism)
- Electroacupuncture
(methods)
- Humans
- Male
- Pain
(etiology, metabolism)
- Pain Management
(methods)
- Rats
- Rats, Wistar
- Receptors, GABA
(genetics, metabolism)
- Receptors, GABA-B
(genetics, metabolism)
- Spinal Cord
(metabolism)
- Thyroid Diseases
(complications, surgery)
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