thromboxane-b2 and Inflammatory-Bowel-Diseases

Topics: Aminosalicylic Acids; Colitis, Ulcerative; Crohn Disease; Humans; Inflammatory Bowel Diseases; Leukotriene B4; Mesalamine; Prostaglandins; Sulfasalazine; Thromboxane B2

The aim of this study was to investigate the effects of the administration of oral arachidonic acid (AA) in rats with or without dextran sulphate sodium (DSS)-induced inflammatory bowel disease. Male Wistar rats were administered AA at 0, 5, 35 or 240 mg/kg daily by gavage for 8 weeks. Inflammatory bowel disease was induced by replacing drinking water with 3 % DSS solution during the last 7 d of the AA dosing period. These animals passed loose stools, diarrhoea and red-stained faeces. Cyclo-oxygenase-2 concentration and myeloperoxidase activity in the colonic tissue were significantly increased in the animals given AA at 240 mg/kg compared with the animals given AA at 0 mg/kg. Thromboxane B2 concentration in the medium of cultured colonic mucosae isolated from these groups was found to be dose-dependently increased by AA, and the increase was significant at 35 and 240 mg/kg. Leukotriene B4 concentration was also significantly increased and saturated at 5 mg/kg. In addition, AA at 240 mg/kg promoted DSS-induced colonic mucosal oedema with macrophage infiltration. In contrast, administration of AA for 8 weeks, even at 240 mg/kg, showed no effects on the normal rats. These results suggest that in rats with bowel disease AA metabolism is affected by oral AA, even at 5 mg/kg per d, and that excessive AA may aggravate inflammation, whereas AA shows no effects in rats without inflammatory bowel disease.

Topics: Animals; Arachidonic Acid; Colitis; Colon; Cyclooxygenase 2; Dextran Sulfate; Diet; Inflammation; Inflammatory Bowel Diseases; Intestinal Mucosa; Leukotriene B4; Macrophages; Male; Peroxidase; Rats, Wistar; Thromboxane B2

Thromboxanes, prostaglandins, reactive oxygen metabolites and pro-inflammatory cytokines are produced in excess in inflammatory bowel disease. Preliminary reports suggest that ridogrel, a thromboxane synthesis inhibitor and receptor blocker, may have therapeutic benefits in ulcerative colitis.. To investigate the anti-inflammatory profile of ridogrel.. The effects of ridogrel on the production of eicosanoids, reactive oxygen metabolites and cytokines by cultured inflamed colorectal mucosal biopsies were made using ELISA and chemiluminescence, reactive oxygen metabolite generation in a cell-free system, and platelet activation using flow cytometry. The effects of oral ridogrel on mucosal release of eicosanoids in two patients with active ulcerative colitis were assessed using rectal dialysis.. Ridogrel significantly reduced the release of thromboxane B2, but not prostaglandin E2 or tumour necrosis factor-alpha, from biopsies (P < 0.01 for 10 microM ridogrel). Ridogrel showed no direct antioxidant activity but significantly reduced reactive oxygen metabolite production from cultured biopsies (P < 0.01 for 10 microM ridogrel). Platelet activation in vitro was inhibited by ridogrel (P /= 10 microM ridogrel). Mean rectal mucosal thromboxane B2 release was reduced to 86% of pre-treatment levels in two patients treated with oral ridogrel.. Its inhibition of mucosal production of thromboxane B2, reactive oxygen metabolites, and of platelet activation, suggests that ridogrel could have a therapeutic role in inflammatory bowel disease.

Topics: Adult; Cytokines; Dinoprostone; Eicosanoids; Female; Gastrointestinal Agents; Humans; Inflammatory Bowel Diseases; Intestinal Mucosa; Male; Middle Aged; Pentanoic Acids; Platelet Activation; Pyridines; Reactive Oxygen Species; Thromboxane B2

Inflammatory bowel disease is associated with increased mucosal release of eicosanoids. Among these, thromboxane A2 has been proposed as a possible inflammatory mediator; its suppression may be a useful therapeutic option.. Using a tissue incubation technique, we compared release of immunoreactive thromboxane B2 by colonic biopsies from patients with ulcerative colitis, Crohn's disease and controls, and assessed the inhibitory effect of picotamide, a thromboxane synthesis inhibitor-receptor antagonist, which has been widely used in Italy for management of ischaemic heart and cerebrovascular disease.. Increased amounts of thromboxane B2 were released from biopsies from patients with active ulcerative colitis (median 238 pg/20 min/mg wet weight (interquartile range 147-325), n = 12) and active Crohn's disease (252 (174-450), 6) compared with those from patients with quiescent ulcerative colitis (95 (61-140), 12) or Crohn's disease (105 (57-201), 13), or controls (136 (64-206), 8). Incubation with picotamide at concentrations between 100 microM and 1 mM reduced thromboxane B2 release (IC50 890 microM).. Since increased thromboxane A2 production may have pathogenetic importance, thromboxane synthesis inhibitor-receptor antagonists such as picotamide merit therapeutic trial in the management of inflammatory bowel disease.

Topics: Adult; Aged; Anti-Inflammatory Agents, Non-Steroidal; Colitis, Ulcerative; Colon; Crohn Disease; Female; Humans; In Vitro Techniques; Inflammatory Bowel Diseases; Intestinal Mucosa; Male; Middle Aged; Phthalic Acids; Rectum; Thromboxane B2

Interleukin 1 beta in biopsy specimens from inflamed colonic mucosa of patients with active inflammatory bowel disease was studied. Compared with normal colonic mucosal biopsy specimens, a significantly greater amount of interleukin 1 beta was present in rectal mucosa before (median (range) 4.3 (2.0-11.8) v 119.2 (30.1-286.8) pg/mg; p less than 0.01) and produced during organ culture (39.1 (9.4-106.8) v 97.6 (28.2-991.6) pg/mg; p less than 0.01). Values of interleukin 1 beta after culture correlated with concentrations of thromboxane B2. Organ culture of inflamed biopsy specimens in the presence of 5 aminosalicylic acid and dexamethasone reduced the amount of interleukin 1 beta detected. At the doses studied, 5 aminosalicylic acid also reduced the amount of leukotriene B4 detected after culture.

Topics: Adult; Aged; Aged, 80 and over; Aminosalicylic Acids; Colitis, Ulcerative; Colon; Crohn Disease; Dexamethasone; Female; Humans; Inflammatory Bowel Diseases; Interleukin-1; Leukotriene B4; Male; Mesalamine; Middle Aged; Organ Culture Techniques; Sulfapyridine; Thromboxane B2