Structural changes in the epithelium of the small intestine and immune cell infiltration of enteric ganglia following acute mucosal damage and local inflammation

An acute enteritis is commonly followed by intestinal neuromuscular dysfunction, including prolonged hyperexcitability of enteric neurons. Such motility disorders are associated with maintained increases in immune cells adjacent to enteric ganglia and in the mucosa. However, whether the commonly used animal model, trinitrobenzene sulphonate (TNBS)-induced enteritis, causes histological and immune cell changes similar to human enteric neuropathies is not clear. We have made a detailed study of the mucosal damage and repair and immune cell invasion following intralumenal administration of TNBS. Intestines from untreated, sham-operated and TNBS-treated animals were examined at 3 h to 56 days. At 3 h, the mucosal surface was completely ablated, by 6 h an epithelial covering was substantially restored and by 1 day there was full re-epithelialisation. The lumenal epithelium developed from a squamous cell covering to a fully differentiated columnar epithelium with mature villi at about 7 days. Prominent phagocytic activity of enterocytes occurred at 1-7 days. A surge of eosinophils and T lymphocytes associated with the enteric nerve ganglia occurred at 3 h to 3 days. However, elevated immune cell numbers occurred in the lamina propria of the mucosa until 56 days, when eosinophils were still three times normal. We conclude that the disruption of the mucosal surface that causes TNBS-induced ileitis is brief, a little more than 6 h, and causes a transient immune cell surge adjacent to enteric ganglia. This is much briefer than the enteric neuropathy that ensues. Ongoing mucosal inflammatory reaction may contribute to the persistence of enteric neuropathy.

Lymphocytes transfer [(14)C]-labeled fatty acids to skeletal muscle in culture; modulation by exercise

Previous studies have shown that lipids are transferred from lymphocytes (Ly) to different cell types including macrophages. enterocytes, and pancreatic beta cells in co-culture This study investigated whether [(14)C]-labeled fatty acids (FA) can be transferred from Ly to skeletal muscle (SM), and the effects of exercise on such phenomenon Ly obtained from exercised (EX) and control (C) male Wistar rats were preloaded with the [(14)C]-labeled free FA palmitic (PA), oleic (OA), linoleic (LA), or arachidonic (AA) Radioactively loaded Ly were then co-cultured with SM from the same Ly donor animals Substantial amounts of FA were transferred to SM being the profile PA = OA > AA > LA to the C group. and PA > OA > LA > AA to the EX group These FA were incorporated predominantly as phospholipids (PA = 66 75%: OA = 63 09%, LA = 43 86%, AA - 47 40%) in the C group and (PA = 63 99% OA = 52 72%, LA = 55 99%, AA = 63 40%) in the EX group Also in this group, the remaining radioactivity from AA, LA, and OA acids was mainly incorpoiated in structural and energetic lipids These results support the hypothesis that Ly are able to export lipids to SM in co-culture Furthermore. exercise modulates the lipid transference profile, and its incorporation on SM The overall significance of this phenomenon in vivo remains to be elucidated. Copyright (C) 2010 John Wiley & Sons, Ltd