Direct measurement of urinary bile acids of infants by high-performance liquid chromatography connected with an enzyme immobilized column.

Tazawa, Yusaku; Yamada, Masaaki; Nakagawa, Michiko; Konno, Tasuke; Tada, Keiya

doi:10.1620/tjem.143.361

Cited by 7 publications

(4 citation statements)

References 21 publications

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“…The use of an ELSD in bile acid analysis is an improvement over other detectors because it does not rely on the optical properties of bile acids or the need for post-or precolumn derivatization associated with colorimetric-based assays (7,8). Previous HPLC-ELSD strategies have employed solvent systems composed of methanol and ammonium acetate solvent mixtures with an elution gradient of the methanol component to achieve complete separation of both conjugated and unconjugated bile acids (9,10).…”

Section: Methods Developmentmentioning

confidence: 99%

Separation and Quantitation of Bile Acids Using an Isocratic Solvent System for High Performance Liquid Chromatography Coupled to an Evaporative Light Scattering Detector

Torchia¹,

Labonté²,

Agellon³

2001

Analytical Biochemistry

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Section: Methods Developmentmentioning

confidence: 99%

Separation and Quantitation of Bile Acids Using an Isocratic Solvent System for High Performance Liquid Chromatography Coupled to an Evaporative Light Scattering Detector

Torchia¹,

Labonté²,

Agellon³

2001

Analytical Biochemistry

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“…Synthesis of the C27 bile acid, 3 ␤ -hydroxy-5-cholestenoic acid is unique to the cholesterol 27-hydroxylase metabolic pathway and it is probably the the sole source of the C24 bile acid, 3 ␤ -hydroxy-5-cholenoic acid, although one cannot exclude a very minor contribution from 24Shydroxycholesterol (38). Both monohydroxy bile acids normally circulate in plasma in nanomolar amounts, but only the latter has been reported in amniotic fluid, meconium, bile, and urine (39)(40)(41)(42). Presumably the C27 acid undergoes further oxidation to the C24 acid in peroxisomes, perhaps exclusively in the liver, since the C24 acid was not identified as a metabolite when 27-hydroxycholesterol was incubated with nonhepatic tissues (28).…”

Section: Monohydroxy Bile Acid Synthesismentioning

confidence: 99%

“…The knowledge that amniotic fluid in early pregnancy contains relatively large amounts of monohydroxy bile acids (39) indicates the existence of a metabolic pathway that begins with C27 hydroxylation. Expression of the CYP27 gene during fetal life can also be inferred from the finding of monohydroxy bile acids in neonatal urine (41,42). Oxysterol 7 ␣ -hydroxylase but not cholesterol 7 ␣hydroxylase is also normally expressed in fetal liver (49).…”

Section: Bile Acid Synthesis In Fetal and Neonatal Lifementioning

confidence: 99%

25R,26-Hydroxycholesterol revisited: synthesis, metabolism, and biologic roles

Javitt

2002

Journal of Lipid Research

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The CYP27 gene is expressed in arterial endothelium, macrophages, and other tissues. The gene product generates sterol intermediates that function as ligands for nuclear receptors prior to their transport to the liver for metabolism, mostly to bile acids. Most attention has been given to 27-hydroxycholesterol as a ligand for LXR activated receptors and to chenodeoxycholic acid as a ligand for farnesoid X activated receptors (FXRs). Expression of the pathway in macrophages is essential for normal reverse cholesterol transport. Thus, ABC transporter activity is upregulated, which enhances cholesterol efflux. Absence of these mechanisms probably accounts for the accelerated atherosclerosis that occurs in cerebrotendinous xanthomatosis. Accumulation of 27-hydroxycholesterol in human atheroma is puzzling and may reflect low levels of oxysterol 7 ␣hydroxylase activity in human macrophages. The same enzyme determines the proportion of mono-, di-, and trihydroxy bile acids synthesized in the liver. Oxysterol 7 ␣hydroxylase deficiency is a molecular basis for cholestatic liver disease. Chenodeoxycholic acid, the major normal end product, downregulates expression of cholesterol 7 ␣ -hydroxylase via the FXR/short heterodimer protein nuclear receptor and thus limits total bile acid production.The challenge is to quantify in a physiologic setting the magnitude of the pathway in different tissues and to further evaluate the biologic roles of all the intermediates that may function as ligands for orphan nuclear receptors or via other regulatory mechanisms. -Javitt, N. B. 25R,26-Hydroxycholesterol revisited: synthesis, metabolism, and biologic roles.

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“…Losses of steroid conjugates have been occasionally observed using Amberlyst A-1 5 while chromatography on SPSephadex is by comparison slow . Carboxymethyl Sephadex LH-20 gel has been used prior to separation on PHP-LH-20 (Tazawa et al, 1984a), although most methods using this anion exchange have not included a cation exchange step 1980a;Onishi et al, 1982;Kamada et al, 1982;Matoba et al, 1986). Hedenborg and Norman (1984; reported that a cation exchanger was not necessary in conjunction with DEAP-LH-20 for serum or urine analysis.…”

Section: Ion Exchange Chromatographymentioning

confidence: 99%