Shen S, Bian J T, Tian J B, Han J S
Neuroscience Research Center, Beijing Medical University.
Sheng Li Xue Bao. 1996 Feb;48(1):89-93.
Previous studies in our laboratory have shown that electroacupuncture (EA) using different frequencies produced differential opioid peptides release in the spinal cord of rats and human beings. In the present study we observed the frequency dependence of substance P (SP) release from rat spinal cord, with the frequencies of EA set at 2, 4, 8, 15, 30 and 100 Hz. The spinal perfusate was collected in 3 periods of 30 min before, during and after EA, and the immunoreactive SP (SP-ir) was measured by radioimmunoassay (RIA). The effectiveness of EA-induced analgesia was assessed by tail flick latency (TFL). Rats showing an increase of TFL over 40% was considered as EA responder. The results showed that in the responders, SP-ir in spinal perfusate showed a moderate decrease during 2 Hz EA, (P < 0.01 compared with baseline level), no change in the 4 Hz EA group, and a marked increase during 8, 15, 30 and 100 Hz EA (P < 0.01), with maximal increase occurring at 15 Hz (P < 0.001). The above results suggest that EA may induce upward or downward modulation in SP-ir release depending on the frequency of EA. However in the non-responder rats no change in spinal fluid SP-ir content was observed. This suggests that changes in SP-ir release have same causal relation with the analgesia induced by EA stimulation.
我们实验室之前的研究表明，使用不同频率的电针（EA）在大鼠和人类脊髓中产生了不同的阿片肽释放。在本研究中，我们观察了大鼠脊髓中P物质（SP）释放的频率依赖性，电针频率设定为2、4、8、15、30和100Hz。在电针前、电针期间和电针后3个30分钟时间段收集脊髓灌流液，通过放射免疫分析（RIA）测定免疫反应性SP（SP-ir）。通过甩尾潜伏期（TFL）评估电针诱导镇痛的效果。TFL增加超过40%的大鼠被视为电针反应者。结果显示，在反应者中，脊髓灌流液中的SP-ir在2Hz电针期间适度下降（与基线水平相比，P<0.01），在4Hz电针组中无变化，在8、15、30和100Hz电针期间显著增加（P<0.01），在15Hz时增加最大（P<0.001）。上述结果表明，电针可能根据电针频率诱导SP-ir释放的上调或下调。然而，在无反应大鼠中，未观察到脊髓液中SP-ir含量的变化。这表明SP-ir释放的变化与电针刺激诱导的镇痛具有相同的因果关系。
