title: Spontaneous and carbachol-evoked in vivo secretion of acetylcholinesterase from the hippocampus of the rat.
abstract: Spontaneous and evoked secretion of acetylcholinesterase from the hippocampus in vivo has been demonstrated by the use of push-pull cannulae. Local perfusion with 10(?5)M carbachol evoked an increase of 104% in acetylcholinesterase release with no accompanying change in butyrylcholinesterase or lactic dehydrogenase. Local or systemic atropine sulphate blocked the carbachol-evoked increase in acetylcholinesterase release, whilst gallamine had no effect. Local perfusion of ?-aminobutyric acid (10(?4)M) also blocked the carbachol-evoked release of acetylcholinesterase but had no effect on the spontaneous release. It is concluded that a soluble form of acetylcholinesterase is secreted from the hippocampus in response to stimulation of muscarinic receptors; this secretion can be influenced by ?-aminobutyric acid, which is present in interneurones in the hippocampus.
authors.affiliation: University Department of Pharmacology, South Parks Road, Oxford, OX1 3QT, U.K.
authors.forename: M E
authors.initials: ME
authors.lastname: Appleyard
authors.forename: A D
authors.initials: AD
authors.lastname: Smith