title: Improved analysis of bile acids in tissues and intestinal contents of rats using LC/ESI-MS.
abstract: To evaluate bile acid (BA) metabolism in detail, we established a method for analyzing BA composition in various tissues and intestinal contents using ultra performance liquid chromatography/electrospray ionization mass spectrometry (UPLC/ESI-MS). Twenty-two individual BAs were determined simultaneously from extracts. We applied this method to define the differences in BA metabolism between two rat strains, WKAH and DA. The amount of total bile acids (TBAs) in the liver was significantly higher in WKAH than in DA rats. In contrast, TBA concentration in jejunal content, cecal content, colorectal content, and feces was higher in DA rats than in WKAH rats. Nearly all BAs in the liver were in the taurine- or glycine-conjugated form in DA rats, and the proportion of conjugated liver BAs was up to 75% in WKAH rats. Similar trends were observed for the conjugation rates in bile. The most abundant secondary BA in cecal content, colorectal content, and feces was hyodeoxycholic acid in WKAH rats and omega-muricholic acid in DA rats. Analyzing detailed BA profiles, including conjugation status, in a single run is possible using UPLC/ESI-MS. This method will be useful for investigating the roles of BA metabolism under physiological and pathological conditions.
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Masahito
authors.initials: M
authors.lastname: Hagio
authors.forename: Megumi
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Michihiro
authors.initials: M
authors.lastname: Fukushima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hara
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ishizuka
mesh_terms: D000818:Animals; D001646:Bile / Q000378:metabolism; D001647:Bile Acids and Salts / Q000378:metabolism*; D002793:Cholic Acids / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid / Q000379:methods*; D003840:Deoxycholic Acid / Q000378:metabolism; D005766:Gastrointestinal Contents; D005998:Glycine / Q000737:chemistry / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D051381:Rats; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013654:Taurine / Q000737:chemistry / Q000378:metabolism
chemical_list: D001647:Bile Acids and Salts; D002793:Cholic Acids; D003840:Deoxycholic Acid; D013654:Taurine; C004821:muricholic acid; C010471:hyodeoxycholic acid; D005998:Glycine