Participation of adrenergic mechanisms in brain acetylcholine release produced by centrophenoxine

The effect of phentolamine (alpha-adrenoceptor antagonist) and propranolol (beta-adrenoceptor antagonist) on the increased brain acetylcholine-releasing effect of centrophenoxine were studied in unanaesthetized cats in which perfusion of the anterior horn of a lateral cerebral ventricle was performed. Phentolamine alone decreased the amount of spontaneously released acetylcholine and did not change the effect of centrophenoxine. Propranolol alone did not change the amount of spontaneously released acetylcholine and reversed the centrophenoxine effect. The effects of centrophenoxine on acetylcholine release are attributed to its action on the presynaptic adrenoceptors (alpha and beta) situated in the cholinergic terminals of structures lying the anterior horn of a lateral cerebral ventricle.