Receptors and Transmission in the Brain-Gut Axis: Potential for Novel Therapies. IV.
GABAB receptors in the brain-gastroesophageal axis.
Blackshaw, L. Ashley.
Nerve-Gut Research Laboratory, Department of Gastroenterology, Hepatology and General
Medicine, Royal Adelaide Hospital, North Terrace, Adelaide, South Australia 5000,
Australia
APStracts 8:0114G, 2001.
GABAB receptors are inhibitory G protein-coupled receptors that are commonly associated with
presynaptic inhibition of transmitter release in the central nervous system. In the brain-
gastroesophageal axis, a role has recently been demonstrated for GABAB receptors on extrinsic
afferent endings within the stomach and esophagus, where they reduce mechanosensitivity. This
action is compounded by inhibition of communication centrally from these afferents in the brain
stem and within central circuits. There is a final peripheral action on the motor pathway where
GABAB receptors reduce output of acetylcholine from vagal preganglionic motoneurons. These
potent, multiple actions of GABAB receptors may have therapeutic benefit by reducing the
triggering of transient lower esophageal relaxations, which are the major cause of
gastroesophageal reflux. An important clinical application is therefore emerging for this recent
discovery.
Received 3 April 2001; accepted in final form 9 May 2001
APS Manuscript Number G143-1.
Article publication pending Am J Physiol Gastrointest Liver Physiol
ISSN 1080-4757 Copyright 2001 The American Physiological Society.
Published in APStracts on 18 June 2001