杏仁核與酸注射引起之慢性肌肉疼痛之相關性

Abstract

慢性肌肉疼痛和其引起之痛覺過敏是難以治療的。利用酸性的生 理食鹽水(ph=4)重複注射於Sprague-Dawley(SD) 大鼠和許多品系的 小鼠的腓腸肌會產生持續的機械性痛覺過敏和慢性肌肉疼痛。此實驗 在研究杏仁核的活化與杏仁核T 型態鈣離子通道對於這種長期痛覺 過敏之發展的必要性。我們利用ERK 免疫化學組織染色和正子斷層 掃描 (PET) 來證實在酸誘導肌肉疼痛的動物中杏仁核受到活化。並 且經預埋大鼠雙側杏仁核的鋼管，注射兩種T型態鈣離子通道的阻斷 劑mibefradil和ethosuximide，可以防止SD大鼠在重複的注射酸性生 理食鹽水之後，對機械性刺激反應閾值下降的情形。綜合以上結果顯 示，杏仁核對於長期肌肉疼痛的產生上扮演重要角色。

Chronic muscle pain and hyperalgesia induced are disabling and difficult to treat. Acidic Saline (pH=4.0) injected repeatedly into the gastrocnemius muscle produce persistent mechanical hyperalgesia and muscle pain in Sprague-Dawley (SD) rats and many mice strains. The objective of the present project was to test the hypothesis that activation of amygdala and amygdala T-type calcium channel is necessary in the development of this chronic hyperalgesia. We used the ERK immunochemistry stain and positron emission tomography (PET) scanner to demonstrate that activation of the amygdale in acid induced pain animals. Cannula was implanted bilaterally in both side of the amygdala of SD rats and two kinds of T-type calcium channel blockers, namely, mibefradil and ethosuximide, were injected. SD rats showed decrease of threshold to mechanical stimulation after repeated injection of acidic saline, and this sensitization phenomenon was prevented by pre-treatment of T-type calcium channel blockers in amygdale. The preliminary results suggest that amygdala play an important role in the expression of chronic muscle pain.