Studies on the turnover of acetylcholine in the brain of rats during the course of acupuncture analgesia

Abstract

The ACh content and turnover in the brain of rat during the course of acupuncture analgesia (AA) were investigated. In electro-acupuncture (EA) group, the pain threshold was significantly higher than that of the control (P<0.0l) and the acetylcholine (ACh) content in the brain increased obviously.

In order to determine the rate of ACh utilization and synthesis, hemicholineum-3 (HC-3) and physostigmine were used as tool drugs to block the synthesis and degradation of ACh respectively. It was discovered that during AA, the ACh utilization rate increased significantly in comparison with the control group. In caudate nucleus it increased to more than twice and in thalamus nearly to twice the amount. At the same time the rate of ACh synthesis also increased. These indicate that the elevation of ACh content in the central nerve system (CNS) is the result of a new dynamic equilibrium between the increase in ACh utilization rate and synthesis rate induced by EA. Reviewing a lot of papers concerned, one can see that the increase in ACh utilization rate is an important evidence that ACh actively participates in the action of AA.

Keywords

acupuncture analgesia / acetylcholine / turnover rate / content / caudate nucleus / thalamus

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