Alteration of prostaglandin E2 and leukotriene B4 synthesis in chronic inflammatory bowel disease.

BACKGROUND: Eicosanoid mediators play an important role in the pathogenesis of chronic inflammatory bowel disease. MATERIALS AND METHODS: The synthesis of prostaglandin E2 and leukotriene B4 in biopsied colonic specimens from patients with inflammatory bowel disease was compared with that from healthy controls. In contrast to surgical resection, biopsy by colonoscopy enabled patients with milder disease to be investigated. RESULTS: In subjects with Crohn's disease or ulcerative colitis, the synthesis of PGE2 was significantly (p < 0.05) increased, whereas synthesis of LTB4 remained unaltered. In addition, no differences in PGE2 and LTB4 production were found in different age groups or sex. CONCLUSION: We conclude that prostaglandin E2, compared to leukotriene B4, is the dominant eicosanoid in moderate inflammatory bowel disease.

Decreased gastric prostaglandin E2 synthesis in patients with gastric ulcers and in smokers.

BACKGROUND/AIMS: Prostaglandin inhibits gastric acid secretion and exerts protective action on the mucosa of the stomach. We studied the synthesis of prostaglandin E2 (PGE2) to determine the role of PGE2 in peptic ulcer disease. MATERIALS AND METHODS: Mucosal biopsies from 22 persons were obtained and incubated. PGE2 was then determined by radioimmunoassay. RESULTS: Compared to healthy subjects, patients with gastric ulcers or gastritis show diminished accumulation of PGE2 in the incubation medium. Other factors like age, gender, and alcohol consumption were also investigated, however, they do not influence endogenous prostaglandin production. In contrast, PGE2 synthesis was found to be decreased in smokers. CONCLUSIONS: Our data indicates a deficiency in endogenous PGE2 synthesis as one cause of gastric ulcerations and offer an explanation of the higher incidence of gastric ulcer disease in subjects with nicotine abuse.