Shen S, Li J, Wang X M, Han J S
Neuroscience Research Center, Beijing Medical University.
Sheng Li Xue Bao. 1996 Dec;48(6):543-50.
Changes in the content of angiotensin II (A II) immunoreactivity (ir) in rat spinal perfusate induced by electroacupuncture (EA) stimulation of different frequencies were measured by radioimmunoassay (RIA). The results were analyzed in relation to the role of opioid receptor. (1) 2 Hz EA produced a 20% (P > 0.05) decrease in A II -ir content in the spinal perfusate. 15 Hz EA produced an even more decrease (62%, P < 0.01), whereas 100 Hz produced a significant increase (65%, P < 0.05). (2) The release in spinal A II -ir produced by 15 Hz EA was reversed by the opioid antagonist naloxone to a of 125% highter than that of the control (P < 0.05), suggesting that 15 Hz EA may accelerate the release of endogenous opioids to suppress the release of A II. (3) This was substantiated by the finding that intrathecal (i.t.) injection of the selective mu agonist ohmefentanyl produced a dramatic suppression (20%, P < 0.05) of A II release, but not by delta and kappa agonist. (4) Intrathecal injection of salarasin, the angiotensin receptor antagonist, produced a significant potentiation of the analgesia produced by 100 Hz EA, but not that produced by 2 or 15 Hz EA. It is concluded that 15 Hz EA may induce the release of endogenous opioids acting on mu opioid receptor so as to suppress A II release, and that 100 Hz EA may accelerate the release of A II serving as a brake for 100 Hz EA-induced analgensia. Removal of the brake by angiotensin antagonist may be advised as an adjunct for the potentiation of 100 Hz EA-induced analgesia.
采用放射免疫分析法（RIA）测定不同频率电针（EA）刺激诱导大鼠脊髓灌流液中血管紧张素II（A II）免疫反应性（ir）含量的变化。结合阿片受体的作用对结果进行分析。（1）2Hz电针使脊髓灌流液中A II -ir含量降低20%（P>0.05）。15Hz电针使其降低更多（62%，P<0.01），而100Hz电针使其显著升高（65%，P<0.05）。（2）阿片受体拮抗剂纳洛酮可使15Hz电针引起的脊髓A II -ir释放逆转，比对照组高125%（P<0.05），提示15Hz电针可能促进内源性阿片类物质释放以抑制A II释放。（3）鞘内（i.t.）注射选择性μ激动剂奥芬太尼可显著抑制（20%，P<0.05）A II释放，而δ和κ激动剂则无此作用，这证实了上述观点。（4）鞘内注射血管紧张素受体拮抗剂沙拉新可显著增强100Hz电针产生的镇痛作用，但对2Hz或15Hz电针产生的镇痛作用无增强作用。结论：15Hz电针可能诱导作用于μ阿片受体的内源性阿片类物质释放，从而抑制A II释放；100Hz电针可能促进A II释放，对100Hz电针诱导的镇痛起制动作用。建议使用血管紧张素拮抗剂去除制动作用，作为增强100Hz电针诱导镇痛的辅助手段。
