TRESK is the most recently reported two-pore domain K^＋ channel, and different from other two-pore domain channels in gene, molecular structure, electrophysiological and pharmacological properties. Although the current knowledge of this potassium channel is inadequate, researches have demonstrated that TRESK is remarkablely linked to acute and chronic pain by activation of calcineurin. The fact that TRESK is sensitive to volatile anesthetics and localization in central nerve system implies that TRESK may play a very important role in the mechanism mediating general anesthesia. The further research of TRESK may contribute to explore the underlying mechanism of some pathological conditions and yield novel treatments for some diseases.
目的观察鞘内注射碳酸酐酶抑制剂乙酰唑胺(ACT)对大鼠切口痛行为的影响。方法所有大鼠术前6天鞘内置管,随机分为5组:假手术组、假手术+ACT组、切口痛组、切口痛+ACT低剂量(2.25μg)组、切口痛+ACT高剂量(22.5μg)组,每组16只。按照Brennan法建立切口痛模型。ACT和生理盐水均在术后d 1鞘内给予。分别于术前d1(基础值)、术后d 1(给药前,给药后30、75、120、165、240min)测定大鼠的热缩足潜伏期(TWL)和机械缩足反射阈值(MWT),并予比较。结果切口痛术后d 1(给药前)与基础值相比TWL、MWT均明显降低(P<0.05);鞘内给予高剂量ACT,与给药前相比,给药后30、75、120 min TWL升高(P<0.05),但不影响大鼠的MWT;与切口痛组相比,切口痛+ACT高剂量组在给药后30、75、120 min TWL明显增高(P<0.05)。结论鞘内给予碳酸酐酶抑制剂ACT部分缓解了切口痛大鼠的热痛觉过敏,但是对机械痛觉过敏没有影响,提示碳酸酐酶可能参与了切口痛的热痛敏过程。
Objective To clarify the role of propofol in controlling incisional pain and its potential effects on the spinal opioid receptor expression. Methods A postoperative model of nociception was established in male Sprague-Dawley rats weighing 200 -250 g. A total of 96 rats were randomly divided into 8 groups. All drugs were administered intravenously either 5 rain pre-operation or 5 rain post-operation. The analgesic effects of systemic propofol were demonstrated by the measurement of a cumulative pain score （ CPS ）. After that, the lumbar enlargement of the spinal cord was removed to evaluate the mRNA level of the μ-opioid receptor （ MOR ） and δ-opioid receptor （ DOR） by RT-PCR. Results CPS and DOR mRNA expressions significantly increased after the operation. Both propofol post-treatment and propofol pre-treatment groups showed significant suppression of the increased CPS and the expression of DOR mRNA evoked by pain stimulation. Interestingly, propofol pre-treatment had a more pronounced effect in decreasing CPS and the expression of DOR mRNA. Furthermore, these observations were dose-dependent. MOR mRNA expression significantly increased after operation in all animals and propofol treatment had no impact on it. Conclusion Based on these findings, we suggest that propofol can serve as a valuable adjunct in acute postoperative pain management. Systemic propofol induces an analgesic effect on acute incisional pain in a dose-dependant manner, and this effect is mediated in the spinal cord and may be associated with the spinal DOR.
