title: In vivo metabolism of leukotriene C4 in germ-free and conventional rats. Fecal excretion of N-acetylleukotriene E4.
abstract: [5,6,8,9,11,12,14,15-3H8]Leukotriene C4 was subcutaneously injected into rats. Substantial amounts of the administered radioactivity were excreted in feces of germ-free and conventional animals during a 72-h period (78 and 64%, respectively). Analyses of fecal extracts by high performance liquid chromatography showed eight radioactive components for each type of animal. One metabolite amounted to 4.6% of the injected radioactivity in germ-free and 0.6% in conventional rats. Its chemical structure, 5-hydoxy-6-S-(2-acetamido-3-thiopropionyl)-7,9-trans-11,14-c is-eicosatetraenoi c acid (N-acetylleukotriene E4) was determined by ultraviolet spectroscopy, fast atom bombardment mass spectrometry, chemical and enzymatic transformations, and confirmed by chemical synthesis. Another metabolite (2.7% of the administered radioactivity in germ-free and 0.5% in conventional rats) was characterized as the 11-trans isomer of the former metabolite. The pathway of formation of these compounds appears to be analogous to the pathway of mercapturic acid biosynthesis.
mesh_terms: D000818:Animals; D001681:Biological Assay; D002851:Chromatography, High Pressure Liquid; D005243:Feces / Q000032:analysis*; D005856:Germ-Free Life; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D017999:Leukotriene E4 / Q000031:analogs & derivatives*; D013058:Mass Spectrometry; D009119:Muscle Contraction / Q000187:drug effects; D051381:Rats; D013189:SRS-A / Q000031:analogs & derivatives* / Q000378:metabolism*
chemical_list: D013189:SRS-A; D017999:Leukotriene E4; C047630:N-acetylleukotriene E4