【摘要】 <正> 最近国内外均有纳洛酮可对抗针刺镇痛的报导(1～3),一般认为针刺镇痛原理与内啡肽系统有关,但这方面的实验大多局限于受体水平,对于针刺镇痛时脑内内啡肽释放情况的动态观察,迄今未见报导。我们采用推挽浂流法(4)及受体结合分析法(5、6),直接观察家兔针刺前后中央灰质中内啡肽的释放变化,看到针刺镇痛时中央灰质浂流液中有一种内啡肽的含量增加,现报告如下。更多还原

【Abstract】 In each of ten rabbits a push-pull cannula was stereotaxically implanted into the central grey according to the atlas of Sawyer’s (P9.5, L19 H-1.5). Three days after surgery, a push-pull perfusion using artificial CSF was carried out with constant rate and temperature, 2 ml of perfusate was collected both before and after electro-acupuncture. It was eluted through a Sephadex G-10 column. Three fractions , Ⅰ (prior to the salt peak), Ⅱ and Ⅲ (after the salt peak) were collected, and assayed for opiate receptor affinity against tritium-labelled dihydromorphine.Each animal underwent three experiments treated as "acupuncture group" and "control group" alternately. After completion of the third experiment the animals were sacrificed., and the position of the cannula was verified according to histological procedures.It was found that the baseline levels of endorphins contents in fraction Ⅰ,Ⅱand Ⅲ, expressed as percentage against the receptor binding of tritium dihydromor-phine were 47.6±3.4 (mean±SE), 44.1±2.7 and 41.7 ±4.4 respectively. Corresponding to leucine enkephalin 18.6,16.3 and 14.6 ng/2ml respectively. After electro-acupuncture for 20 min, there was a significant increase of endorphin level in fraction Ⅰ of animals with more than two-fold rise of pain threshold (consizered as "effective acupuncture group" ), the percentage against the receptor binding of 3H-dihydromorphine increased from 41.4±5.84 to 69.5 ±5.72 (p<0.01, t test). But it was not the case in the "ineffective acupuncture group", or "control group". As to the endorphin activity in fraction Ⅱ and Ⅲ, no significant changes were found before and after electro-acupuncture.2 ml of artificial CSF was chroma -tographed in a similar way as the perfusate, the percentage against the receptor binding of 3H-dihydromorphine was below 10; 0.5μg of leucine enkephalin dissolved in 2 ml artificial CSF vvas eluted through the same G-10 column, and its activity peak was behind the salt peak.The present results suggest that the analgesic effect of acupuncture is related to the increased release of endorphin fraction Ⅰ in the central grey, and it seems unlikely that this fraction Ⅰ is enkephalin.更多还原