100Hz电针刺受时大鼠脑和脊髓k受体结构特性的改变

西方采用放射配体结合实验研究了１００ＨＺ电针耐受发生发展过程中大鼠脑和脊髓Ｋ受体结构特性的变化。大鼠每天给予１００ＨＺ电针１次,连续７ｄ。分别在电针的第１、３、５、７天取不同脑区进行观察。

Changes in the binding characteristics of central kappa-opioid receptor during the development of 100 Hz electroacupuncture (EA) tolerance in rats

The effect of repetitive 100 Hz EA stimulation on the characteristics of binding of Kopioid receptors in discrete brain regions and the spinal cord of rats was investigated by radioligand binding assay. 100 Hz EA was administered once a day (30 min) for 7 d.Changes in Bmax and Kd of K opioid receptors of 4 discrete brain regions (cortex,midbrain, pons-medulla and striatum) and spinal cord were observed at d 1, 3, 5 and 7 ,respectively. It was found that the numbers (Bmax) of K opioid receptors of all the brain regions observed were decreased during the development of 100 Hz EA tolerance with a differential time course . In rat cortex and pens-medulla, a marked down regulation of Kopioid receptors occurred within 24 h and remained at al low level throughout the observation. The Bmax of K receptor in spinal cord showed a bell-shaped curve, i. e., upregulation in the first 5 days and down regulation at d 7. In contrast a slow and steady down regulation was found in the midbrain and striatum, matching the coutrse of develop - ment of 100 Hz EA tolerance. No significant changes in Kd of 3H]-U69593 were found except for a decrease of Kd in midbrain In conclusion, administration of 100 Hz EA 30min per day for 7 consecutive days resulted in a significant down regulation of K opioid receptor in CNS, especially in midbrain and striatum.