Anticholinergic pharmacological studies of the lower oesophageal sphincter: importance of the technique of pressure recording.

To assess lower oesophageal sphincter (LOS) response to anticholinergic drugs, six healthy subjects were repeatedly studied according to two experimental procedures. In Method A, water-filled catheters were infused by a classical syringe pump and the recording assembly permitted only one orifice to be stationed within the LOS. The study was not conducted in a double-blind fashion. Method B was a double-blind study, in which water-filled catheters were infused by a hydraulic infusion system and the recording assembly permitted two or three orifices to be stationed within the LOS. The results showed that: Whatever the method used, LOS responses to pentagastrin (0.1, 0.3, 0.6, 1.2 micrograms/kg) were not significantly different under control experiments. With Method A, atropine infusion markedly reduced LOS responses to pentagastrin. With Method B, atropine infusion did not modify LOS responses to pentagastrin. These results raise the possibility that technical factors could account for conflicting reports of the effect of atropine on the pentagastrin-stimulated lower oesophageal sphincter.