thromboxane-a2 and Crohn-Disease

Prostanoids are important for the pathogenesis of chronic inflammatory bowel diseases as mediators of inflammatory, immune and allergic reactions. The levels of thromboxane B2(TXB2), the stable hydrolysis product of thromboxane A2(TXA2) were determined in blood plasma of patients with chronic inflammatory bowel diseases. The platelet malondialdehyde (MDA) formation was determined as an indicator of the TXA2 synthetase activity. The TXB2 concentrations were measured radioimmunologically. The platelet MDA formation induced by N-ethylmaleimide was investigated with the thiobarbituric acid reaction. The investigated patients (n = 10) suffering from ulcerative colitis had a significant increasing (p less than 0.02) of the platelet MDA formation (mean = 4.39 nmol/10(9) platelets) in comparison to the normal group (n = 20; mean = 2.87; nmol/10(9) platelets). The increasing of TXB2 levels was not significantly different than in normal control subjects. The plasma concentrations of 6-keto-PGF1 were situated on the limit of detection.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Colitis, Ulcerative; Crohn Disease; Humans; Middle Aged; Recurrence; Thromboxane A2; Thromboxane B2

Intestinal epithelial and mononuclear cells were isolated from normal colonic mucosa and from intestinal mucosa of inflammatory bowel disease patients. Prostanoid synthesis by primary cultures of intestinal mononuclear cells were four to six fold higher than its synthesis by primary cultures of epithelial cells. Prostaglandin E2, prostacyclin and thromboxane A2 synthesis by cultured mononuclear cells isolated from inflamed ileal mucosa of four Crohn's disease patients: 5.6 +/- 1.2; 3.2 +/- 1.9 and 2.4 +/- 1.4 (mean +/- SE) ng/1 X 10(6) cells were significantly higher than their respective synthesis by cultured mononuclear cells isolated from uninflamed ileal mucosa isolated from the same patients: 0.8 +/- 0.1; 0.3 +/- 0.1 and 0.2 +/- 0.03 ng/1 X 10(6) cells or from normal colonic mucosa: 1.5 +/- 0.3; 0.3 +/- 0.1 and 0.5 +/- 0.1 (N = 12) ng/1 X 10(6) cells. Prostanoid synthesis by primary cultures of intestinal mononuclear cells isolated from colonic mucosa of five ulcerative colitis patients was enhanced but not significantly different from its synthesis by cells isolated from normal subjects. These results suggest that the enhanced intestinal prostanoid synthesis in active Crohn's disease is derived from stimulated local mononuclear cells and may have an important role in the pathogenesis of the disease.

Topics: Cells, Cultured; Colitis, Ulcerative; Colon; Crohn Disease; Dinoprostone; Epithelium; Epoprostenol; Humans; Intestinal Mucosa; Leukocytes; Prostaglandins; Prostaglandins E; Thromboxane A2; Thromboxanes