HISTOLOGY AND HISTOPATHOLOGY

Cellular and Molecular Biology

Neuronal anomalies and normal muscle morphology at the hypomotile ileocecocolonic region of patients affected by idiopathic chronic constipation

M.-S. Faussone-Pellegrini1, A. Infantino2, P. Matini1, A. Masin2, B. Mayer3 and M. Lise2

1Department of Human Anatomy and Histology, University of Florence, Florence, Italy, 2Institute of Clinic Surgery II, University of Padua, Padua, Italy and 3Institute of Pharmacology and Toxicology, University of Graz, Graz, Austria

Offprint requests to: Prof. M.S. Faussone-Pellegrini, Department of Human Anatomy and Histology, Section of Histology, Viale G. Pieraccini 6, I-50134, Florence, Italy. Fax: 0039. 55. 4271385. e-mail: s_faussone@cesit1.unifi.it

 

Summary. Patients suffering from idiopathic slow-transit chronic constipation have a delayed colonic transit referable to a decrease or loss of propagating contractions. Myogenic and/or neural mechanisms have been implicated in the pathophysiology of this dysfunction and neuronal abnormalities have been described at the ascending, descending and sigmoid colon. The morphology and motile behaviour of the ileocecocolonic region, which in healthy subjects regulates cecum filling and emptying, have never been investigated in such disease. Therefore, we endo-scopically ascertained whether a motility impairment was present at these junctional areas and neither spontaneous nor provoked occlusive contractions were found at the cecocolonic junction. Light and electron microscope examination of the entire colon revealed apparently normal features of neurons, smooth muscle cells and interstitial cells of Cajal, while immunohisto-chemistry and quantitative analysis demonstrated neuronal anomalies at the junctional areas. These anomalies consisted of low total neuron density and significantly few VIP-immunoreactive neurons at the two enteric plexuses, significantly few NOS-immuno-reactive neurons at the myenteric plexus and significantly more NOS-immunoreactive neurons at the submucous plexus. These findings exclude a myopathy and demonstrate the existence of a neuropathy. In particular, the presence at the ileocecocolonic region of few VIP- and NO-producing neurons suggests that there might be a reduced VIP and NO production which may result in a compromised relaxation and/or onset of propagating contractions, slowing down bolus transit. The presence at the proximal colon of such an abnormality might explain why left colectomy and/or cecorectal anastomosis are unsuccessful in patients with this disease. Histol. Histopathol. 14, 1119-1134 (1999)

Key words: Constipation, Histochemistry, Ileo-cecocolonic junctions, Nitric oxide, VIP

DOI: 10.14670/HH-14.1119