Colonic neuroendocrine peptide levels in patients with chronic idiopathic slow transit constipation

The motility disorders in patients with slow-transit constipation have been attributed to a disturbance in the peptidergic innervation of the colonic enteric nervous system. The nature of this disturbance is, however, controversial. In the present study 7 patients with long-standing severe slow- transit constipation were included, and normal tissues from the colon of 6 patients, which had undergone colonectomy because of polyp, chronic diverticulitis, prolapsis and volvulus were used as controls. The concentrations of several neuroendocrine peptides were measured in tissue extracts by radioimmuno-assays. The level of pancreatic polypeptide was high in 2 patients and low in one patient. Peptide YY level was high in 3 patients and low in one patient, and that of neuropeptide Y was high in 4 patients. Somatostatin and vasoactive intestinal polypeptide levels were high in 3 patients and substance P concentration was low in 3 patients. Neurotensin level was high in one patient and low in another patient. Galanin concentration was low in 2 patients and high in one patient. Gastrin-releasing peptide level was high in one patient and that of enkephalin was high in 2 patients. All patients had altered concentrations of several neuroendocrine peptides except one, who had only a low level of galanin. It is concluded that patients with slow-transit constipation have disturbed neuroendocrine peptides in common, though the nature of this disturbance varies between patients and in most patients several neuroendocrine peptides were affected. This may explain the controversial results obtained in previous studies.