piperidines and Enteritis

Topics: Child; Child, Preschool; Clinical Trials as Topic; Diarrhea, Infantile; Enteritis; Female; Humans; Infant; Infant, Newborn; Male; Piperidines

The intestinal epithelium serves as an essential barrier to the outside world and is maintained by functionally distinct populations of rapidly cycling intestinal stem cells (CBC ISCs) and slowly cycling, reserve ISCs (r-ISCs). Because disruptions in the epithelial barrier can result from pathological activation of the immune system, we sought to investigate the impact of inflammation on ISC behavior during the regenerative response. In a murine model of αCD3 antibody-induced small-intestinal inflammation, r-ISCs proved highly resistant to injury, while CBC ISCs underwent apoptosis. Moreover, r-ISCs were induced to proliferate and functionally contribute to intestinal regeneration. Further analysis revealed that the inflammatory cytokines interferon gamma and tumor necrosis factor alpha led to r-ISC activation in enteroid culture, which could be blocked by the JAK/STAT inhibitor, tofacitinib. These results highlight an important role for r-ISCs in response to acute intestinal inflammation and show that JAK/STAT-1 signaling is required for the r-ISC regenerative response.

Topics: Acute Disease; Animals; Apoptosis; Cytokines; Enteritis; Inflammation; Intestinal Mucosa; Intestine, Small; Janus Kinases; Mice; Mice, Transgenic; Piperidines; Pyrimidines; Pyrroles; Regeneration; Signal Transduction; STAT1 Transcription Factor; Stem Cells

Administration of abdominal radiotherapy results in small intestinal motor dysfunction. We have developed a rat radiation enteritis model that, after exposure in vivo, shows high-amplitude, long-duration (HALD) pressure waves in ex vivo ileal segments. These resemble in vivo dysmotility where giant contractions migrate both antegradely and retrogradely. Mediation of these motor patterns is unclear, although enteric neural components are implicated. After the induction of acute radiation enteritis in vivo, ileal segments were isolated and arterially perfused. TTX, hexamethonium, atropine, or the selective muscarinic antagonists pirenzepine (M(1)), methoctramine (M(2)), and 1,1-dimethyl-4-diphenylacetoxypiperidinium iodide (4-DAMP; M(3)) were added to the perfusate. The baseline mean rate per minute per channel of HALD pressure waves was 0.35 +/- 0.047. This was significantly reduced by TTX (83.3%, P < 0.01), hexamethonium (90.3%, P < 0.03), and atropine (98.4%, P < 0.01). The HALD pressure wave mean rate per minute per channel was significantly reduced by pirenzepine (81.1%, P < 0.03), methoctramine (96.8%, P < 0.001), and 4-DAMP (93.1%, P < 0.03) compared with predrug baseline data. As an indicator of normal motility patterns, the frequency of low-amplitude, short-duration pressure waves was also assessed. The mean rate per minute per channel of 5.15 +/- 0.98 was significantly increased by TTX (19%, P < 0.05) but significantly reduced by pirenzepine (35.1%, P < 0.02) and methoctramine (75%, P < 0.0003). However, the rate of small-amplitude pressure waves was not affected by hexamethonium, atropine, or the M(3) antagonist 4-DAMP. The data indicate a role for neuronal mechanisms and the specific involvement of cholinergic receptors in generating dysmotility in acute radiation enteritis. The effect of selective M(3) receptor antagonism suggests that M(3) receptors may provide specific therapeutic targets in acute radiation enteritis.

Topics: Animals; Diamines; Enteritis; Gastrointestinal Motility; Ileum; Male; Manometry; Piperidines; Pirenzepine; Radiation Injuries, Experimental; Rats; Rats, Sprague-Dawley; Receptors, Muscarinic

Clostridium difficile is a spore-forming, anaerobic, gram-positive bacillus that releases two main virulence factors: toxins A and B. Toxin A plays an important pathogenic role in antibiotic-induced diarrhea and pseudomembranous colitis, a condition characterized by intense mucosal inflammation and secretion. Agonist activity at A2A adenosine receptors attenuates inflammation and damage in many tissues. This study evaluated the effects of a new selective A2A adenosine receptor agonist (ATL 313) on toxin A-induced injury in murine ileal loops. ATL 313 (0.5 to 5 nM) and/or the A2A adenosine receptor antagonist (ZM241385; 5 nM) or phosphate-buffered saline (PBS) were injected into ileal loops immediately prior to challenge with toxin A (1 to 10 microg/loop) or PBS. Intestinal fluid volume/length and weight/length ratios were calculated 3 h later. Ileal tissues were collected for the measurement of myeloperoxidase, adenosine deaminase activity, tumor necrosis factor alpha (TNF-alpha) production, histopathology, and detection of cell death by the TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling) method. Toxin A significantly increased volume/length and weight/length ratios in a dose-dependent fashion. ATL 313 treatment significantly (P < 0.05) reduced toxin A-induced secretion and edema, prevented mucosal disruption, and neutrophil infiltration as measured by myeloperoxidase activity. ATL 313 also reduced the toxin A-induced TNF-alpha production and adenosine deaminase activity and prevented toxin A-induced cell death. These protective effects of ATL 313 were reversed by ZM241385. In conclusion, the A2A adenosine receptor agonist, ATL 313, reduces tissue injury and inflammation in mice with toxin A-induced enteritis. The finding of increased ileal adenosine deaminase activity following the administration of toxin A is new and might contribute to the pathogenesis of the toxin A-induced enteritis by deaminating endogenous adenosine.

Topics: Adenosine A2 Receptor Agonists; Adenosine Deaminase; Animals; Apoptosis; Bacterial Toxins; Enteritis; Enterotoxins; Ileal Diseases; Ileum; Male; Mice; Piperidines; Tumor Necrosis Factor-alpha

An open study of loperamide in seven chronic diarrhoea patients who were inadequately controlled by previous anti-diarrhoeal therapy is reported. All patients were well controlled by small amounts of loperamide and most could not eat a normal diet. No side-effect were reported.

Topics: Adult; Chronic Disease; Colitis; Diarrhea; Diverticulitis, Colonic; Enteritis; Humans; Loperamide; Piperidines

Topics: Animals; Cattle; Cattle Diseases; Dexetimide; Diarrhea; Drug Therapy, Combination; Enteritis; Female; Male; Piperidines

Topics: Acute Disease; Bacterial Infections; Butyrates; Child; Child, Preschool; Diarrhea, Infantile; Enteritis; Gastroenteritis; Gastrointestinal Agents; Humans; Infant; Infant, Newborn; Piperidines; Virus Diseases

Topics: Biomedical Research; Colchicine; Colectomy; Colitis; Colitis, Ulcerative; Colonic Diseases; Colonic Diseases, Functional; Crohn Disease; Diabetic Neuropathies; Diarrhea; Diphenoxylate; Diverticulitis; Diverticulitis, Colonic; Drug Therapy; Dysentery; Dysentery, Amebic; Enteritis; Gastroenteritis; Humans; Piperidines; Postgastrectomy Syndromes; Postoperative Complications; Toxicology; Virus Diseases