Introduction: Ulcerative colitis and Crohn's disease are two main disease entities that belong to the group of inflammatory bowel diseases (IBD). Chronic inflammatory process concerning intestinal mucosal membrane causes structural and functional changes of intestinal nervous system. This phenomenon is called the plasticity of the nervous system and is due to the ability of nerve cells to adapt to changing environmental conditions. The resulting alterations of intestinal neurons' chemical code are augmentation, inhibition or initiation of the neurotransmitters' synthesis (synthesis "de novo"). The role of neuroprotective transmitters - galanine (GAL), vasoactive intestinal peptide (VIP) and pituitary adenosine cyclase activating peptide (PACAP) seems to be important in the pathogenesis of inflammatory bowel diseases. They are responsible for the regulation of intestinal contraction and modification of ions' transport in the intestinal epithelium. They also diminuate the inflammation by modulation of the proinflammatory chemokines and cytokines production.
The aim: of the study was to analyse the changes in the nerve fibres' containing GAL, VIP and/or PACAP, density in the mucosal membrane of children with ulcerative colitis (UC) with different Clinical activity index.
Material and methods: the study included 33 children hospitalised due to UC with different activity and 9 children in the control group, after exclusion of IBD. All the studied patients underwent colonoscopic examination with colon mucosa biopsies. Histology and immunochemistry of mucosal samples were analysed. Those studies helped to assess the changes in the number of nerve fibres containing analysed transmitter substances in the mucosal membrane of the colon.
Results: the results showed a statistically significant diminuation of nerve fibres containing analysed neurotransmitters number in colon mucosa samples of children with UC. There were no statistically significant changes in number of nerve fibres dependent on the clinical activity index of UC.
Conclusions: the process of degradation present in UC is accompanied by the important diminuation on neurotransmitter containing fibres number. However, their density is not dependent of the clinical activity of the disease.