下丘脑室旁核ATP敏感性钾离子通道参与大鼠炎性痛调节的作用研究

Contributions of K_(ATP) within the paraventricular nucleus in the modulation of inflammatory pain in rats

目的：探讨下丘脑室旁核 ATP 敏感性钾离子通道（ KATP通道）在大鼠炎性痛中的作用。方法裔 SD 大鼠（250~280 g）,采用随机数字法分为5组（每组6只）：正常组（ Normal组）、完全弗氏佐剂致炎性痛组（ CFA组）、生理盐水组（ Saline组）、KATP通道特异性激动剂组（ Diaoxide组）和激动剂溶媒组（ Vehicle组）。以热痛敏刺激仪检测各组大鼠热缩足潜伏期（ TWL）,观察痛行为学变化；以免疫荧光技术观察室旁核KATP通道和脊髓背角c-Fos阳性细胞数的变化。并观察KATP通道激动剂对大鼠痛行为和脊髓背角c-Fos表达的影响。结果①与术前和Saline组相比,CFA组大鼠炎症侧后足术后d 1、d 3和d 7的TWL降低（P〈0.05）,CFA组术后d 3、d 7的KATP阳性细胞数减少（P〈0.01）,脊髓背角c-Fos阳性细胞数增加（ P〈0.01）；②与Vehicle组相比,激动剂组大鼠热痛觉过敏减轻（ P〈0.01）,脊髓背角c-Fos阳性细胞数减少（P〈0.01）。结论下丘脑室旁核KATP通道可能与CFA所致炎性痛的发生机制相关。

Aim To explore the role of KATP in the pa-raventricular nucleus in inflammatory pain. MethodsMale Sprague-Dawley rats,250~280 g, were randomly assigned into 5 groups （ each, n =6 ）： Normal group, Saline group （ for control, subcutaneous injection of 100 μl of saline into the plantar surface of the left hindpaw） , CFA group （ subcutaneous injection of 100μl of complete freund＇s adjuvant into the plantar sur-face of the left hindpaw） , Vehicle group （ treated with dimethylsulfoxide）, KATP selective agonist group（trea-ted with diaoxide） . Rats in each group were tested for TWL with radiant heat apparatus. Immunofluorescent technique was used to label KATP in PVN and c-Fos in lumber spinal cord. Three days after injected with CFA, a selective KATP agonist, diaoxide, was injected into one side of PVN to test its effect on inflammatory pain and c-Fos expression in lumber spinal cord. Re-sults ① Compared with pre-operation and saline group, rats showed significantly lower TWL on day 1, 3, 7 after injection of CFA;the numbers of KATP posi-tive cells were significantly lower; the numbers of c-Fos positive cells were significantly higher. ② Com-pared with those of vehicle group, TWL and the num-ber of c-Fos in lumber spinal cord were both signifi-cantly lower after injection of diaoxide into one side of PVN. Conclusion KATP in PVN is related to inflam-matory pain.