[Synthesis of eicosanoids in the colonic mucosa in patients with ulcerative colitis]

The synthesis of cyclooxygenase (CO) and lipoxygenase (LO) metabolites of arachidonic acids, such as prostaglandins (PG) E2, F2 alpha, 6-keto-P1 alpha, thromboxane B2 (TB2), leukotriene B4 (LTB4) and hydroxyeicosatetraenic acids (HETEA) in the biopsy specimens of the colonic mucosa (CM) was studied in vitro in 30 patients aged 17-66 years who had ulcerative colitis (UC) of various severity and extent. The biopsy specimens of CM from 10 patients with the irritable bowel syndrome were used for comparison. A proportional severity of the disease and increased synthesis of CO and LO metabolites in CM was ascertained in a phase of UC. In the early phase of clinical remission (on the average, following 4 weeks of therapy), there was a comparative reduction in the level of eicosanoids with the preserved high production of TB2 and LO derivatives (LTB4 and HETEA). At the same time, in patients with severe UC, a higher synthesis of LTB4 and HETEA and PG was preserved. The predominance of CM production of eicosanoids having aggregative, vasoconstrictor, and proinflammatory effects (less coefficients of 6-keto-PGF1 alpha/TB2 and PG/LTB4 + ETEA), which had been detected in a phase of UC exacerbation, was preserved in a phase of remission development, by forming the metabolic basis for recurrence of the process.