vasoactive-intestinal-peptide and Swine-Diseases

The aim of the present study was to investigate potential interrelationships between immune and neural elements of Peyer's patches in normal pigs (n=8) and in pigs infected experimentally with Brachyspira hyodysenteriae and suffering from swine dysentery (n=8). Assessment of tissue concentration of neuropeptides by enzyme linked immunosorbent assay revealed increased levels of galanin (GAL) and substance P (SP) in samples from the infected animals. In contrast, concentrations of vasoactive intestinal polypeptide (VIP) and somatostatin (SOM) were similar in both groups. Immunohistochemistry demonstrated reactivity of nerve fibres with antibodies specific for dopamine β hydroxylase, vesicular acetylcholine transporter, SOM, GAL, VIP and SP in the interfollicular region and peripheral areas of the Peyer's patch lymphoid follicles. In the dysenteric pigs, the GAL-positive nerve fibres were more numerous and more intensely labelled than those in the normal animals. Flow cytometry revealed a decreased percentage of CD21(+) lymphocytes and lymphocytes expressing T-cell receptor (TCR)-γ, with or without CD8 (TCR-γ(+)CD8(-) and TCR-γ(+)CD8(+)), in the dysenteric pigs as compared with the normal animals. Percentages of other lymphocyte subsets (CD2(+), CD4(+), CD5(+), CD8(+), CD5(-)CD8(+)) were comparable between the groups. Immunohistochemical investigations generally correlated with results obtained by flow cytometry related to lymphocyte subpopulations. Swine dysentery can therefore affect neuroimmunomodulatory processes in the ileal Peyer's patch, in addition to the large intestine. GAL and SP may play a specific role in this neuroimmune cross-talk.

Topics: Animals; Brachyspira hyodysenteriae; Enzyme-Linked Immunosorbent Assay; Female; Flow Cytometry; Galanin; Gram-Negative Bacterial Infections; Ileum; Immunohistochemistry; Lymphocyte Subsets; Peyer's Patches; Somatostatin; Substance P; Swine; Swine Diseases; Vasoactive Intestinal Peptide

The study was performed on 20 piglets of both sexes. The control group consisted of 10 healthy piglets, the experimental, group included 10 piglets with symptoms of gastroenteritis. All the animals were subjected to euthanasia at the age of 21 or 35 days (weaning), or 7 days after weaning, and immunohistochemical and histopathological examinations were performed on all of them. Immunohistochemical examinations of the experimental piglets included additional tests made on five piglets with gastroenteritis, characterized by poor general condition. Histopathological examinations of the pancreas revealed retrogressive changes, which might result from hemodynamic disorders. Changes in the localization of SOM and VIP found in the pancreas suggested inhibition of pancreatic enzyme synthesis in piglets with diarrhea. The co-localization of GAL and dopamine beta-hydroxylase (D beta H--a key enzyme of the noradrenaline synthesis pathway) in perivascular nerve fibers could lead to considerable vasospasms in the pancreas, resulting in deeper hypoxia of the organ. Immunohistochemical and histopathological examinations confirmed the results of biochemical analyses, indicating failure of the pancreatic exocrine function in piglets with gastroenteritis.

Topics: Animals; Case-Control Studies; Diarrhea; Dopamine beta-Hydroxylase; Female; Galanin; Gastroenteritis; Immunohistochemistry; Male; Metabolic Diseases; Pancreas; Somatostatin; Swine; Swine Diseases; Vasoactive Intestinal Peptide

Limited studies have shown that in intestinal schistosomosis, the enteric nervous tissue becomes inflamed, disrupted and destroyed by granulomas and peptides, amines and neurofilaments contents are altered. Therefore, immunoreactivities of vasoactive intestinal peptide and substance P were correlated to pathological lesions in the large intestine from pigs infected with Schistosoma japonicum. Ganglia situated within or near granulomas showed ganglionitis, and necrosis of neurons as well as infiltration by eosinophils, mast cells, lymphocytes, plasma cells, neutrophils and macrophages. The inner submucous and mucous plexuses were the most damaged. In all categories of inflamed areas, the vasoactive intestinal peptide-like immunoreactive was reduced in all plexuses whereas, that of substance P was increased both in the enteric nerve plexuses and enterochromaffin cells in lightly, moderately and severely inflamed tissues. However, both peptides were highly diminished or absent in very severe lesions and areas surrounding schistosome eggs and mature worms laying eggs in the submucosal veins. The alterations of the levels of vasoactive intestinal peptide and substance P were correlated with severity of inflammation. Our observations show alterations of vasoactive intestinal peptide and substance P contents in the local microenvironment in the vasoactive intestinal peptide- and substance P-mediated reflex pathways which regulate intestinal motility, epithelial transport and modulate immunity. These changes could cause alterations in bowel motility, electrolyte and fluid secretion, vascular and immune functions during S. japonicum infections in the pig. This may, therefore, partly play a role in the pathobiology of migration and egress of schistosome eggs as well as influence trapping of eggs in granulomas, and account for diarrhoea, loss of body weight and failure to thrive, which are recorded in schistosomosis.

Topics: Animals; Cecum; Colon; Enteric Nervous System; Immunohistochemistry; Intestinal Mucosa; Schistosoma japonicum; Schistosomiasis japonica; Substance P; Swine; Swine Diseases; Vasoactive Intestinal Peptide

Using an immunohistochemical technique, the presence and distribution of vasoactive intestinal polypeptide (VIP) was investigated in cryostat sections, both tangential and transverse, of the fetal pig's stomach. In all fetuses and in all gastric segments investigated, VIP-like immunoreactive (IR) nerve-cell bodies were seen in all intramural ganglia, and VIP-IR nerve fibres were found in all layers of the gastric wall except the tunica serosa. Consequently, VIP-IR nerve fibres were found to form a periglandular network, to accompany arterioles, to interconnect the intramural ganglia, to encircle both VIP-IR-negative and -positive neurons, and were found in all muscle layers. Despite the fact that VIP-IR seems to be restricted to the intramural nervous elements, some non-specific-reacting VIP-IR glandular cells were noticed in the basal parts of the fundic, antral and pyloric gastric glands. The distribution pattern of VIP in the fetal pig resembles that of the adult pig. This suggests a possible functional role for VIP during fetal life and/or puts forward the suggestion that the stomach of a fetal pig from the second half of the gestation period is prepared, from then on, for postnatal function. High similarities with regard to the general distribution pattern of VIP in the stomach have also been noted between the fetal pig and humans, proving once more that the fetal pig can serve as a good animal model in several research areas. Finally, the morphological data provided here may, combined with the physiological significance of VIP, contribute to a better insight into the physiopathology of economically important gastro-intestinal disorders in the pig, such as gastric ulceration.

Topics: Animals; Disease Models, Animal; Fetus; Immunohistochemistry; Nerve Fibers; Neurons; Stomach; Stomach Ulcer; Swine; Swine Diseases; Vasoactive Intestinal Peptide