cinnamoylglycine and hippuric-acid

The renal proximal tubule is essential for removing organic solutes and exogenous medications from the circulation. We evaluated diurnal, prandial, and long-term biological variation of 4 candidate endogenous markers of proximal tubular secretion.. We used LC-MS to measure plasma and urine concentrations of hippurate (HA), cinnamoylglycine (CMG), indoxyl sulfate (IS), and. Plasma concentrations of secreted solutes varied over the 24-h baseline period. Diurnal variation was greatest for HA, followed by CMG, IS, and PCS. Plasma concentrations of HA (. Plasma concentrations of HA, CMG, IS, and PCS fluctuate within individuals throughout the day and over weeks. Renal clearances of these secreted solutes, which serve as estimates of renal proximal tubule secretion, are also subject to intraindividual biological variation that can be improved by additional plasma measurements.

Topics: Adult; Biomarkers; Chromatography, Liquid; Cresols; Female; Glycine; Hippurates; Humans; Indican; Kidney Tubules, Proximal; Male; Sulfuric Acid Esters; Tandem Mass Spectrometry

Formaldehyde (FA) is a ubiquitous compound used in a wide variety of industries, and is also a major indoor pollutant emitted from building materials, furniture, etc. Because FA is rapidly metabolized and endogenous to many materials, specific biomarkers for exposure have not been identified. In this study, we identified small metabolite biomarkers in urine that might be related FA exposure. Mice were allowed to inhale FA (0, 4, 8 mg/m3) 6 h per day for 7 consecutive days, and urine samples were collected on the 7th day of exposure. Liquid chromatography coupled with time of flight-mass spectrometry and principal component analysis (PCA) was applied to determine alterations of endogenous metabolites in urine. Additionally, immune toxicity studies were conducted to ensure that any resultant toxic effects could be attributed to inhalation of FA. The results showed a significant decrease in the relative rates of T lymphocyte production in the spleen and thymus of mice exposed to FA. Additionally, decreased superoxide dismutase activity and increased reactive oxygen species levels were found in the isolated spleen cells of exposed mice. A total of 12 small molecules were found to be altered in the urine, and PCA analysis showed that urine from the control and FA exposed groups could be distinguished from each other based on the altered molecules. Hippuric acid and cinnamoylglycine were identified in urine using exact mass and fragment ions. Our results suggest that the pattern of metabolites found in urine is significantly changed following FA inhalation, and hippuric acid and cinnamoylglycine might represent potential biomarker candidates for FA exposure.

Topics: Administration, Inhalation; Animals; Biomarkers; Chromatography, High Pressure Liquid; Female; Formaldehyde; Glycine; Hippurates; Male; Mass Spectrometry; Mice; Mice, Inbred BALB C; Principal Component Analysis; Reactive Oxygen Species; Respiratory Hypersensitivity; Spleen; Superoxide Dismutase