辣椒素受体在内皮素-1引起热痛觉过敏中的作用

Role of vanilloid receptors in thermal hyperalgesia induced by intraplantar endothelin-1 administration

目的研究辣椒素受体对内皮素-1(ET-1)引起热痛觉过敏的影响。方法选用辣椒素受体基因敲除小鼠(KO小鼠)及其野生型C57BL/6J小鼠(WT小鼠),分为KO组与WT组,两组分别按3、10、30、100pmol剂量足底注射ET-1(溶于10μl磷酸盐缓冲液,n=6)。测量注药前和注药后15、30、45及60min时逃避时间(PWT)。结果ET-1引起两组动物PWT降低,在WT组降低幅度更明显,WT组PWT随着ET-1剂量的增加而降低,而KO组PWT在剂量为30pmol时降低最为明显。结论ET-1引起的热痛觉过敏部分通过辣椒素受体起作用。

Objective To assess the role of vaniUoid receptor （VR） in thermal hyperalgesia induced by intraplaniar endothelin-1 （ET-1） injection. Methods VR gene-knockout mice （KO group） and wild type C57BL/6J mice （WT group） in 3 subgroups were subjected to intraplantar administration of ET-1 at the doses of 3, 10, 30 and 100 pmol （dissolved in 10 pA of PBS, pH 7.4, n=6 in each group）, respectively. The latency time of paw withdrawal （PWT） from heat irradiation stimulation was recorded before injection and 15, 30, 45 and 60 min after injection. Results ET-1 induced thermal hyperalgesia in both groups. The mice in WT group showed a more sharply shortened PWT than those in KO group. ET-1 decreased PWT as the dose administered increased in WT group, which was different from the responses of the KO mice. At the dose of 100 pmol of ET-1, no further decrement of latency time was observed in WT group, whereas such response occurred at 30 pmol in KO group. Conclusion Intraplantar injection of ET- 1 induces thermal hyperalgesia mediated partially by VR.