酸敏感离子通道抑制剂阿米洛利对切口痛大鼠痛行为的影响

Effects of acid sensing ion channels inhibitor amiloride on pain behavior in a rat model of post-incision pain

目的探讨酸敏感离子通道（acid sensing ion channels，ASICs）抑制剂阿米洛利（amiloride）对大鼠切口痛模型痛行为的影响及其机制。方法成年雄性SD大鼠58只，按随机数字表法选取4只用于足底皮肤ASIC3免疫荧光检测，30只用于痛行为学检测，24只用于Westernblot检测脊髓背角pERK1／2表达。痛行为学和Westernblot检测的大鼠随机分为3组：对照组（C组）、切口痛模型组（I组）和阿米洛利组（A组），术毕A组大鼠切口局部浸润amiloride溶液200嵋（20μ1）。检测各组大鼠术前24h和术后2h、4h、8h、12h、24h时间点的机械缩足阈值（PWMT）和热缩足潜伏期（PWTL）值及术后4h脊髓pERK1／2表达。结果ASIC3表达在大鼠足底皮肤真皮层及表皮层深部。术前3组大鼠基础PWMT值和PWTL值分别为：C组[（23．15±5．10）g，（11．32±1．21）s]，I组[（23．25±5．69）g，（11．75±2．01）S]，A组[（23．63±4．96）g，（11．47±1．96）S]（P〉0．05）。术后2h、4h、8h、12h、24h，I组和A组大鼠PWMT值和邢汀L值均小于C组（P〈0．05）；术后2h、4h,8h，A组大鼠PWMT值和PWTL值分别为[（13．75±3．25）g，（9．95±1．32）S]、[（14．05±3．75）g，（9．17±2．11）S]、[（9．75±2．74）g，（8．11±1．22）s]，较I组明显增高（P〈0．05）。术后4h，I组大鼠脊髓pERK1／2表达较C组增加（P〈0．05）；A组大鼠脊髓pERK1／2表达较I组降低（P〈0．05）。结论ASIC3通过激活ERK1／2信号通路介导大鼠切口痛模型术后疼痛，其作用可以被阿米洛利抑制。

Objective To explore the effects and underlying mechanisms of acid sensing ion channels （ASICs） on pain behavior in a rat model of post-incision pain. Methods Fifty-eight adult male Sprague Dawley rats were used in this study,four rats were used for test, thirty rats were employed for pain behavior test, and twenty-four rats were used for Western blot. Rats used for pain behavior test and Western blot were randomly divided into 3 groups ： control group （ C group）, incision pain model group （ I group） and amiloride group （A group）. Plantar skin of rats in A group were infiltrated with 20 μl（200 μg）amiloride solution. Paw withdrawal mechanical threshold（PWMT） and paw withdrawal thermal latency（PWTL） of all rats in pain behavior test was tested at 24 h preoperative,2 h,4 h, 8 h, 12 h,2g h postoperative. Western blot was tested at 4 h postoper- ative. Results Immunofluorescence test displayed ASIC3 was expressed in plantar skin of all rats. The basal level of PWMT and PWTL of all rats in three groups was C group（（23.15 ±5.10）g, （11.32 ±1.21）s） ,I group （ （23.26± 5.69 ） g, （ 11.75± 2.01 ） s）, A group （ （23.63 ± 4.96 ） g, （ 11.47 ±1.96 ） s ） respectively, which was no significantly difference （P 〉 0.05 ）. PWMT and PWTL of I group and A group was significantly lower than that of C group at all time points postoperative （ P 〈 0.05） ; PWMT and PWTL of A group was at 2 h（ （ 13.75± 3.25）g,（9.96 ± 1.32）s）,4 h（（14.05 ±3.75）g, （9.17 ±2.11）s）,8 h（（9.75 ±2.74）g; （8.11 ± 1.22） s） postoperative,which was significantly higher than that of I group （P 〈 0.05 ）. Compared with that of C group, the level of pERK1/2 expression was significantly increased in I group at 4 h postoperative （P〈 0.05 ） ,which could be inhibited by amiloride local infiltration （P 〈 0.05 ）. Conclusion ASIC3 can mediate incision pain in a rat model of post-incision pain,through pERK1/2 signaling pathway,which can be inhibited by amiloride.