目的 检测毫米波急性辐照后SD大鼠脊髓P物质(SP)和c-fos表达的变化,探索毫米波痛觉效应的机制.方法 采用毫米波(35GHz,40W/cm2)一次性辐照SD大鼠局部皮肤0s(对照组)、30s、1min、3min,采用Real-time RT-PCR和Western blotting检测辐照后0min、5min、10min、1h、3h大鼠对应节段脊髓SP、c-fos mRNA、c-fos蛋白的表达水平.结果 毫米波辐照30s后各时间点辐照部位相应节段脊髓SP和c-os mRNA表达与对照组比较无明显差异.毫米波辐照1min后第10min辐照部位相应节段脊髓SP和c-fos mRNA表达显著上调(P＜0.05,P＜0.01),此后下降至对照组水平.毫米波辐照3min后第5min、10min和1h辐照部位相应节段脊髓SP和c-fos mRNA表达显著上调(P＜0.01,P＜0.05),于3h时间点下降至对照组水平.毫米波辐照30s及1min后各时间点辐照部位相应节段脊髓c-fos蛋白表达与对照组比较无明显差异.毫米波辐照3min后第5min和10min辐照部位相应节段脊髓c-fos蛋白表达水平显著上调(p＜0.01),此后下降至对照组水平.结论 毫米波急性辐照后皮肤SP含量增加可能与毫米波辐照导致的热疼痛刺激诱导对应节段脊髓SP和c-fos的表达增加有关.%Objective To observe the expression changes in substance P (SP) and c-fos in rat spinal cord after acute millimeter-wave (MMW) exposure, and explore the mechanism of thermal hyperalgesia at the spinal level. Methods The back skin of SD rats was exposed to 35 GHz MMW (40W/cm2) for Os (control group), 30s, 1 min, or 3min. The corresponding segment of the spinal cord was taken at 0min, 5min, 10min, 1h and 3h after MMW irradiation for total RNA and protein extraction. The expressions of SP and c-fos mRNA were measured by real-time RT-PCR, and the expression of c-fos protein was detected by Western blotting. Results No significant difference was found between the control group and irradiation groups in SP and c-fos mRNA expression in the corresponding segment of spinal cord after MMW irradiation for 30s. After MMW irradiation for 1min, the SP and c-fos mRNA expressions in the corresponding segment of spinal cord increased significantly at lOmin time point, and then decreased to the level of control group. After MMW irradiation for 3min, the SP and c-fos mRNA expression in the corresponding segment of spinal cord increased significantly at 5min, 10min and 1h time points, and decreased to the level of control group at 3h. No significant change was found in c-fos protein expression in the corresponding segment of spinal cord after MMW irradiation for 30s and lmin. After MMW irradiation for 3min, the c-fos protein expression in the corresponding segment of spinal cord increased significantly at 5min and 10min time point, and then decreased to the level of control group. Conclusion The increase of SP expression in rat skin after MMW irradiation may be related to the increase of SP and c-fos expressions in the corresponding segment of the spinal cord induced by thermal pain stimulation.
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