Blockade by Morphine of Acetylcholine Release from the Caudate Nucleus in the Midpontine Pretrigeminal Cat.

摘要

The effects of morphine on the resting and evoked release of H3-acetylcholine from the caudate nucleus into the perfusate of the push-pull cannula in the unanesthetized, midpontine, pretrigeminally transected cat was studied. Morphine was observed to reduce, in a dose-dependent fashion, the amount of tritium-labeled acetylcholine appearing in the push-pull effluent. Moreover, the increase in output observed following the local electrical stimulation of caudate tissue was also blocked. The pharmacological specificity of the effect was demonstrated by the ability of naloxone, the specific opitate antagonist, to reverse the depressant action of morphine on the release of acetylcholine. (Author)