title: Altered leukotriene B4 metabolism in colonic mucosa with inflammatory bowel disease.
abstract: BACKGROUND
  omega-Oxidation is regarded as the major pathway for leukotriene B4 (LTB4) metabolism. Very little is known about it in colonic mucosa with inflammatory bowel disease (IBD).
  
  
  METHODS
  We investigated the metabolic ratio of omega-oxidation to LTB4 biosynthesis in colonic mucosa from patients with IBD and control subjects. After incubation of colonic mucosa with 14C-arachidonic acid and ionophore A23187, we separated LTB4 and its omega-oxidative metabolites by high-performance liquid chromatography.
  
  
  RESULTS
  The rate of LTB4 omega-oxidation was comparable to the rate of its biosynthesis. The metabolic ratio was significantly decreased in inflamed mucosa with ulcerative colitis.
  
  
  CONCLUSIONS
  LTB4 omega-hydroxylase activity is an important factor in regulating LTB4 level in colonic mucosa, and the increased LTB4 level in inflamed mucosa with IBD, especially ulcerative colitis, is caused by decreased LTB4 omega-hydroxylase activity and increased 5-lipoxygenase activity.
authors.affiliation: Third Dept. of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Ikehata
authors.forename: N
authors.initials: N
authors.lastname: Hiwatashi
authors.forename: Y
authors.initials: Y
authors.lastname: Kinouchi
authors.forename: H
authors.initials: H
authors.lastname: Yamazaki
authors.forename: K
authors.initials: K
authors.lastname: Ito
authors.forename: T
authors.initials: T
authors.lastname: Toyota
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism; D003093:Colitis, Ulcerative / Q000378:metabolism*; D003106:Colon / Q000378:metabolism*; D003424:Crohn Disease / Q000378:metabolism*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000378:metabolism*; D007975:Leukotriene B4 / Q000378:metabolism*; D008297:Male; D008875:Middle Aged
chemical_list: D007975:Leukotriene B4; D001094:Arachidonate 5-Lipoxygenase