Effects of postganglionic nerve stimulation in oesophageal achalasia: an in vitro study

The functional postganglionic innervation of isolated smooth muscle strips from the oesophagogastric junction was examined in specimens taken from six achalasia patients and seven controls. Muscle strips representing either the longitudinal or the circular layer were prepared and mounted in organ baths and isometric tension was recorded. Electrical field stimulation, selectively exciting nerves, was applied. Strips from the circular layer from controls relaxed during field stimulation, an effect that was the result of stimulation of noncholinergic, non-adrenergic, inhibitory nerves. Circular muscle strips from achalasia patients contracted during field stimulation, an effect that was caused by muscarinic receptor activation. In one patient, atropine reversed the contraction to a relaxation. Longitudinal muscle strips contracted in response to stimulation in both controls and achalasia patients. This response was abolished by atropine. In conclusion the function of postganglionic inhibitory nerve fibres to the circular layer of the oesophagogastric junction is severely impaired in achalasia, while there is a conspicuous, functional cholinergic innervation.