title: Eicosanoid formation by mammalian intestine. Effects of some intestinal secretagogues.
abstract: Intestinal tissues of man, rat, mouse, guinea-pig and rabbit were preincubated with laxatives, homogenised, and incubated with [14C]arachidonic acid. After extraction into chloroform, the eicosanoids were separated by thin layer chromatography. Metabolism of [14C]arachidonic acid into prostaglandins (PGs), and the lipoxygenase products LTB4 and 5-HETE, was stimulated by ricinoleic acid (100 micrograms/ml) or phenolphthalein (100 micrograms/ml), and to a lesser extent by picosulphate (125 micrograms/ml) and sulfosuccinate (200 micrograms/ml). Mannitol (500 micrograms/ml) had no effect. Indomethacin (1 microgram/ml) inhibited the stimulation of PG formation. The dual pathway inhibitor BW755C (1 microgram/ml) reduced the formation of prostaglandins, LTB4 and 5-HETE. In some experiments on rat colon, prostanoids were separated from lipoxygenase products, characterised by their chromatographic mobility and quantitated (relative amounts PGE2 greater than PGF2 alpha greater than TXB2 greater than PGD2). Their formation was enhanced by ricinoleic acid (100 micrograms/ml) and inhibited by either indomethacin or BW 755C (1 microgram/ml). The present results indicate that mammalian isolated gut tissue can convert [14C]arachidonic acid into both cyclo-oxygenase and lipoxygenase products, and support the suggestion that eicosanoids may participate in the laxative effect of some secretagogues.
mesh_terms: D015772:4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyrazol-3-amine; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism; D002400:Cathartics / Q000494:pharmacology; D003106:Colon / Q000378:metabolism; D004537:Eicosanoic Acids / Q000096:biosynthesis*; D006168:Guinea Pigs; D006801:Humans; D007082:Ileum / Q000378:metabolism; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000187:drug effects; D051379:Mice; D011720:Pyrazoles / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012277:Ricinoleic Acids / Q000494:pharmacology; D013045:Species Specificity
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001095:Arachidonic Acids; D002400:Cathartics; D004537:Eicosanoic Acids; D011720:Pyrazoles; D012277:Ricinoleic Acids; D016718:Arachidonic Acid; D015772:4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyrazol-3-amine; D007213:Indomethacin