Nitrergic and vipergic neurons associated with decreased amount of calcitonin gene-related peptide in the enteric plexus of sigmoid colon in diverticular disease

Abstract

Objective : Diverticular disease (DD) is frequently observed in elderly patients, significantly affecting life quality and expectancy in aging populations. An eminent cause of diverticula formation appears to be altered colonic motility, followed by changes of the enteric nervous system (ENS). Vasoactive intestinal peptide (VIP) and nitric oxide (NO) are the primary relaxant agents of the intestinal musculature. Calcitonin gene- related peptide (CGRP) is involved in a variety of physiological processes within the alimentary tract. These include nociception, immunomodulation, secretion and gastrointestinal motility. The aim of the study was to reveal associations of CGRP with VIP- ergic and nitrergic neurons within myenteric and submucosal plexuses, suggesting an altered relaxation mechanism during DD. Methods : Samples from patients undergoing surgery for colorectal carcinoma served as control ( n = 10) and as asymptomatic DD ( n = 10). Samples for symptomatic DD ( n = 10) were obtained from patients after recurrent attacks of diverticulitis. Double immunohistochemical staining for NO synthase 1 (NOS1) or VIP and CGRP or its receptors – calcitonin receptor- like receptor (CRLR) and receptor activity modifying protein 1 (RAMP1) – was performed on full- thickness sections of sigmoid colon and analyzed with quantitative fluorescence microscopy. Results: [...].