Immunohistochemical evidence of the co-localisation of cocaine and amphetamine regulatory peptide with neuronal isoform of nitric oxide synthase, vasoactive intestinal peptide and galanin within the circular muscle layer of the human caecum

The enteric nervous system consists of about one hundred million of neurons. In big mammals (including humans) intestinal enteric neuronal cells are grouped into three types of intramural ganglia located within myenteric, as well as outer and inner submucosal plexuses, which are connected by numerous nerve fibres. Both nerve fibres and cell bodies located in the gastrointestinal tract utilise a broad spectrum of active substances. One of them is cocaine- and amphetamine-regulated transcript peptide (CART). The goal of the current study was to determinate the distribution and degree of co-localisation of CART with substances taking part in intestinal motor activity by double labelling immunofluorescence technique. During the study CART-, neuronal isoform of nitric oxide synthase (nNOS)-, vasoactive intestinal peptide (VIP)- and/or galanin (GAL) — like immunoreactive (LI) nerve fibres in the circular muscle layer of the human caecum were observed in all patients studied. The degree of co-localisation of particular substances with CART depended on their type. The majority of CART-LI fibres contained simultaneously nNOS, slightly lower degree of co-localisation was observed in the case of the VIP, while simultaneously CART- and GAL-positive nerve fibres were observed less often

Protective Intestinal Effects of Pituitary Adenylate Cyclase Activating Polypeptide

Pituitary adenylate cyclase activating polypeptide (PACAP) is an endogenous neuropeptide widely distributed throughout the body, including the gastrointestinal tract. Several effects have been described in human and animal intestines. Among others, PACAP infl uences secretion of intestinal glands, blood fl ow, and smooth muscle contraction. PACAP is a well-known cytoprotective peptide with strong anti-apoptotic, anti-infl ammatory, and antioxidant effects. The present review gives an overview of the intestinal protective actions of this neuropeptide. Exogenous PACAP treatment was protective in a rat model of small bowel autotransplantation. Radioimmunoassay (RIA) analysis of the intestinal tissue showed that endogenous PACAP levels gradually decreased with longer-lasting ischemic periods, prevented by PACAP addition. PACAP counteracted deleterious effects of ischemia on oxidative stress markers and cytokines. Another series of experiments investigated the role of endogenous PACAP in intestines in PACAP knockout (KO) mice. Warm ischemia–reperfusion injury and cold preservation models showed that the lack of PACAP caused a higher vulnerability against ischemic periods. Changes were more severe in PACAP KO mice at all examined time points. This fi nding was supported by increased levels of oxidative stress markers and decreased expression of antioxidant molecules. PACAP was proven to be protective not only in ischemic but also in infl ammatory bowel diseases. A recent study showed that PACAP treatment prolonged survival of Toxoplasma gondii infected mice suffering from acute ileitis and was able to reduce the ileal expression of proinfl ammatory cytokines. We completed the present review with recent clinical results obtained in patients suffering from infl ammatory bowel diseases. It was found that PACAP levels were altered depending on the activity, type of the disease, and antibiotic therapy, suggesting its probable role in infl ammatory events of the intestine

Zearalenone-induced changes in the lymphoid tissue and mucosal nerve fibers in the porcine ileum

This is the first study to examine zearalenone-(ZEN) induced changes in the immune system of the ileum and substance P-(SP-) and vasoactive intestinal peptide-(VIP-) immunoreactive nerve fibers in the mucosa, which participate in the regulation of intestinal functions under physiological conditions and during pathological processes. The aim of this study was also to identify potential relationships between selected immune and neural elements in ileal Peyer's patches in pigs that were and were not exposed to ZEN. The experiment was performed on 10 prepubertal gilts divided into two groups: the experimental group (n=5) where ZEN was administered at 0.1 mg kg-1 feed day-1 for 42 days, and the control group (n=5) which was administered a placebo. The tissue levels of cytokines were determined by enzyme-linked immunosorbent assay which revealed elevated concentrations of IL-12/23 40p and IL-1 ß in animals exposed to ZEN. Flow cytometry revealed a lower percentage of CD21+ lymphocytes in pigs exposed to ZEN in comparison with control animals. The tissue levels of neuropeptides were evaluated in the dot blot procedure which demonstrated higher concentrations of VIP and SP in experimental pigs. In experimental animals, numerous VIP-like immunoreactive processes were observed, and SP-immunoreactive nerve fibers formed a very dense network. Our results demonstrate for the first time that ZEN can modify the chemical coding of nerve structures in the gastrointestinal system. Those modifications can be attributed to ZEN's impact on estrogen receptors or its pro-inflammatory properties, and they reflect changes that take place in the nervous system at the transcriptional, translational and metabolic level

Somatostatin as an Active Substance of Enteroendocrine Cells in the Canine Digestive Tract in Physiological Conditions and during Inflammatory Bowel Disease

The aim of the present investigation is to examine the changes in the number of somatostatin-like immunoreactive (SOM-LI) enteroendocrine cells in various parts of the canine gastrointestinal (GI) tract during canine inflammatory bowel disease (IBD). The distribution of SOM-LI enteroendocrine cells was studied using the double-labeling immunofluorescence technique with antisera against chromogranin A (CgA; used here as a marker of enteroendocrine cells) and somatostatin (SOM). Evaluation of the number of CgA-positive cells, which also contained SOM in the mucosal layer of canine stomach, duodenum, jejunum and descending colon was based on the counting of such cells per unit area (0.1 mm 2 ). In physiological conditions, the number of SOM-LI enteroendocrine cells has been shown to constitute 5.30±2.07 in the stomach, 2.23±0.56 in the duodenum, 1.86±0.48 in the jejunum and 1.19±0.36 in the descending colon. Canine IBD caused an increase in the number of cells studied in the stomach (to 9.55±1.46) and the jejunum (to 3.84±1.16), while the changes observed in the duodenum and the descending colon have not been statistically significant. The obtained results suggest that SOM-LI enteroendocrine cells, as well as somatostatin, may be involved in pathological processes during canine IBD. Moreover, this study can be treated as the first step of application of SOM and/or its analogues in the treatment of canine IBD in the future

Distribution and chemical coding patterns of cocaine- and amphetaminer-egulated transcript - like immunoreactive (CART - LI) neurons in the enteric nervous system of the porcine stomach cardia

The aim of this study was to determine the presence of cocaine- and amphetamine-regulated transcript-like immunoreactive (CART-LI) neurons and co-localisation of CART with vesicular acetylcholine transporter (VAChT), neuronal nitric oxide synthase (n-NOS), vasoactive intestinal polypeptide (VIP), substance P (SP) and leu-enkephalin (LENK) in the enteric nervous system of the porcine gastric cardia by using a double-labelling immunofluorescence technique. CART-LI neurons were observed in the myenteric plexus (18.2}2.6%). A dense network of CART-LI nerve fibers was mainly observed in the muscular layer. CART showed co-localization mainly with VAChT, n-NOS, VIP and to a lesser degree with LENK and SP. Distribution of CART and its co- ocalization with other neurotransmitters suggest that this peptide plays an important role in gastric motility in the pig