脊髓旋磁场作用时间与角速度对痛阈影响的实验研究

Effect of rotating magnetic field on pain threshold in rats spinal cord： an analysis from processing time and angular velocity

目的观察旋转恒磁场不同作川时间及不同角速度对大鼠甩尾痛闽及机械缩足痛闽（MWT）的影响。方法实验一：将48只雌性SD大鼠按照随机数字表法分为8组，根据测试时间点的不同分别定为处理腑组（对照组1，处理后10、20、30、60min组和处理60rain停后10、20、30rain组．每组6只。以恒定转速（7300r／min）旋转磁场处理大鼠腰椎，于相应时间点分删测定大鼠甩尾反射潜伏期（TFL）及MWT．并对结果进行统计学分析。实验二：将40只雌性大鼠按照随机数字表法分为4组，每组10只。分别测定6300r／min、6800r／min、7300r／min、7800r／min不同角速度的旋转磁场处理大鼠30min后的TFL及MWT，对结果进行统计学分析。结果实验一：与对照组相比．大鼠经旋转磁场处理后10、20、30、60min后TFL均有明昆提高，差异均有统计学意义（心0．05）；停止转动后TFL开始缩短，停后10、20min与对照组比较差异均有统计学意义（P〈O．05）。大鼠MWT则于处理后30、60rain及停后10min较对照组柯明显提高，差异均有统计学意义（P〈0．05）。停后30min恢复至处理前水平。实验二：TFL随着转速的提高而延氏，6300r／min组、6800r／min组与7300r／min组、7800r／min组比较，是异均有统计学意义（P〈0．05）。7800r／min组与6300r／min组MWT比较差异行统计学意义（P〈0．05）。结论旋转磁场处理一定时间后可提升大鼠痛闽，停止处理后阈值的升高有短暂的后效应。在一定范围内痛阈随转速的升高而升高。旋磁镇痛可能成为无创镇痛的新方法。

Objective To observe the effects of rotating magnetic field on the tail-flick latency （TFL） and mechanical withdrawal threshold （MWT） of rats and analyze it from processing time and angular velocity. Methods Forty-eight female SD rats were randomly assigned to 8 groups （n=6）, which would be determined by 8 different time points （before treatment, treating for 10, 20, 30 and 60 min, 10, 20 and 30 rain after treatment）. The magnetic plate rotated near the lumbar of the rat at an angular velocity of 7300 r/min and the TFL and MWT with yon Frey hair test were determined at each time point. The second experiment was carried out on 40 female rats at an angular velocity of 6300, 6800, 7300 and 7800 r/min, respectively; TFL and MWT were determined 30 rain after treatment. The data were statistically analyzed. Results The first experiment was concluded as follows： compared with that before treatment, TFL was statistically increased at treating forl0, 20, 30 and 60 min （P〈0.05）. The TFL gradually became shorten after the treatment, but it was still significantly longer 10 and 20 min after the treatment as compared with that before treatment （P〈0.05）. MWT increased significantly at treating for 30 and 60 min, and 10 rain after treatment as compared with that before treatment （P〈0.05）. Thesecond experiment showed that TFL significantly went up as the angular velocity increased （P〈0.05）. Significantly difference on MWT was found between the angular velocity of 7800 and 6300 r/min. Conclusion Pain threshold can be increased by rotating magnetic field following the increase of processing time and the angular velocity at a certain range, indicating that the rotating magnetic field might be a potential non-invasive pain alleviating method.