title: Simultaneous characterization of bile acids and their sulfate metabolites in mouse liver, plasma, bile, and urine using LC-MS/MS.
abstract: Sulfation is a major metabolic pathway involved in the elimination and detoxification of bile acids (BAs). Several lines of evidence are available to support the role of sulfation as a defensive mechanism to attenuate the toxicity of accumulated BAs during hepatobiliary diseases. Individual BAs and their sulfate metabolites vary markedly in their physiological roles as well as their toxicities. Therefore, analytical techniques are required for the quantification of individual BAs and BA-sulfates in biological fluids and tissues. Here we report a simple, sensitive, and validated LC-MS/MS method for the simultaneous quantification of major BAs and BA-sulfates in mouse liver, plasma, bile, and urine. One-step sample preparation using solid-phase extraction (for bile and urine) or protein precipitation (for liver and plasma) was used to extract BAs and BA-sulfates. Base-line separation of all analytes (unsulfated- and sulfated BAs) was achieved in 25min with a limit of quantification of 1ng/ml. This LC-MS/MS method was applied to simultaneously quantify BAs and BA-sulfates in both male and female mouse tissues and fluids. Less than 3% of total BAs are present in the sulfate form in the mouse liver, plasma, and bile, which provides strong evidence that sulfation is a minor metabolic pathway of BA elimination and detoxification in mice. Furthermore, we report that the marked female-predominant expression of Sult2a1 is not reflected into a female-predominant pattern of BA-sulfation.
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE 68198, United States.
authors.forename: Jiangeng
authors.initials: J
authors.lastname: Huang
authors.forename: Sai Praneeth R
authors.initials: SP
authors.lastname: Bathena
authors.forename: Iván L
authors.initials: IL
authors.lastname: Csanaky
authors.forename: Yazen
authors.initials: Y
authors.lastname: Alnouti
mesh_terms: D000818:Animals; D001646:Bile / Q000187:drug effects; D001647:Bile Acids and Salts / Q000032:analysis*; D001649:Bile Duct Diseases / Q000378:metabolism; D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D005260:Female; D008099:Liver / Q000187:drug effects; D008107:Liver Diseases / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010949:Plasma / Q000187:drug effects; D012737:Sex Factors; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014556:Urine
chemical_list: D001647:Bile Acids and Salts