Regulatory peptides in the lower esophageal sphincter of man.

Smooth muscle specimens were taken from the lower esophageal sphincter of patients suffering from achalasia or hiatus hernia with gastro-esophageal reflux. The specimens were analysed for neurohormonal peptides using immunochemistry and immunocytochemistry. Control specimens were obtained from patients subjected to esophageal resection because of esophageal cancer. The concentration of vasoactive intestinal polypeptide (VIP) was higher and the VIP nerve supply greater in patients with hiatus hernia than in control patients. The VIP nerve supply and the content of this peptide was lower in patients with achalasia than in controls. The same tendency was observed for substance P and enkephalin although the changes in their concentrations were not statistically significant. Enkephalin fibers were few, both in specimens from control patients and from patients with hiatus hernia; they could not be detected in specimens from patients with achalasia. Never fibers containing somatostatin or gastrin/cholecystokinin could not be detected in any of the groups and somatostatin and gastrin/cholecystokinin could not be measured in extracts of the lower esophageal sphincter. We propose that changes in the concentration of neuropeptides may at least contribute to manifestations of achalasia and of decreased lower esophageal sphincter pressure and gastro-esophageal reflux.