Chen X H, Han J S
Department of Physiology, Beijing Medical University, People's Republic of China.
Behav Brain Res. 1992 Apr 10;47(2):143-9. doi: 10.1016/s0166-4328(05)80120-2.
The cross-tolerance technique was used to analyze the receptor mechanisms of analgesia induced by electroacupuncture (EA) of 2 Hz, 100 Hz, or 2-15 Hz. (1) Rats were given EA stimulation of 2 Hz, 100 Hz and 2-15 Hz for 30 min with 30 min intervals successively. The percentage increase in tail-flick latency (TFL) was taken to indicate the intensity of EA analgesia. Rats made tolerant to repeated intrathecal injection of the mu-opioid agonist ohmefentanyl (OMF, 15 pmol, Q2h x 5) or the delta-opioid agonist DPDPE (10 nmol, Q2h x 5) showed a cross tolerance to both 2 Hz- and 2-15 Hz-, but not to 100 Hz-EA analgesia; and rats made tolerant to kappa-opioid agonist dynorphin-(1-13) (5 nmol, Q2h x 5) showed a cross-tolerance to 100 Hz- and 2-15 Hz-, but not to 2 Hz-EA analgesia; (2) Rats made tolerant to 2-15 Hz EA showed cross-tolerance to either 2 Hz- or 100 Hz-EA analgesia; (3) Rats made tolerant to either 2 Hz- or 100 Hz-EA were still reactive to 2-15 Hz-EA. The results indicate that 2 Hz-EA analgesia is mediated by mu- and delta-receptors, 100 Hz-EA analgesia by kappa-receptor, and 2-15 Hz-EA analgesia by combined action of mu-, delta- and kappa-receptors in the spinal cord of the rats.
采用交叉耐受技术分析2Hz、100Hz或2 - 15Hz电针（EA）诱导镇痛的受体机制。（1）大鼠依次接受2Hz、100Hz和2 - 15Hz的EA刺激，每次30分钟，间隔30分钟。甩尾潜伏期（TFL）的增加百分比用于表示EA镇痛的强度。对鞘内重复注射μ阿片受体激动剂奥芬太尼（OMF，15pmol，每2小时一次，共5次）或δ阿片受体激动剂DPDPE（10nmol，每2小时一次，共5次）产生耐受的大鼠，对2Hz和2 - 15Hz的EA镇痛均表现出交叉耐受，但对100Hz的EA镇痛无交叉耐受；对κ阿片受体激动剂强啡肽 -（1 - 13）（5nmol，每2小时一次，共5次）产生耐受的大鼠，对100Hz和2 - 15Hz的EA镇痛表现出交叉耐受，但对2Hz的EA镇痛无交叉耐受；（2）对2 - 15Hz EA产生耐受的大鼠，对2Hz或100Hz的EA镇痛表现出交叉耐受；（3）对2Hz或100Hz EA产生耐受的大鼠，对2 - 15Hz的EA仍有反应。结果表明，2Hz的EA镇痛由μ和δ受体介导，100Hz的EA镇痛由κ受体介导，2 - 15Hz的EA镇痛由大鼠脊髓中μ、δ和κ受体的联合作用介导。
