We have recently demonstrated that the major biliary metabolite of 5-fluorouracil (FUra) in cancer patients is a conjugate of the FUra catabolite 2-fluoro-beta-alanine (FBAL) and cholic acid (D.J. Sweeny, S. Barnes, G. Heggie, and R.B. Diasio. Proc. Natl. Acad. Sci. USA, 84:5439-5443, 1987). This finding prompted us to further examine the metabolism and biliary excretion of clinically relevant concentrations of the fluoropyrimidines FUra and 5-fluoro-2'-deoxyuridine (FdUrd) using the isolated perfused rat liver. During infusion of fluoropyrimidines, rates of appearance of metabolites in bile were similar with both 1 microM FUra and 1 microM FdUrd but were 9-fold higher with 25 microM FUra. Analysis by high performance liquid chromatography demonstrated that unmetabolized fluoropyrimidines and known catabolites (i.e., FBAL) accounted for less than 15% of the total metabolites in bile and that the majority of the biliary metabolites were eluted as three distinct nonpolar compounds. Fast atom bombardment-mass spectrometry demonstrated that these unique metabolites had molecular weights of 497 (peak 1), 497 (peak 2), and 481 (peak 3). These metabolites were hydrolyzed by cholylglycine hydrolase to FBAL and unconjugated bile acids that were identified by gas chromatography-mass spectrometry to be alpha-muricholic acid (peak 1), cholic acid (peak 2), and chenodeoxycholic acid (peak 3). Thus, the major biliary metabolites of FUra and FdUrd were identified as N-(bile acid)-FBAL conjugates. While the N-(bile acid)-FBAL conjugates were the major metabolites in bile, dihydroFUra was the major (greater than 70%) metabolite eliminated into perfusate. In summary, these results demonstrate that FUra and FdUrd undergo similar metabolism in the isolated perfused rat liver and, as was observed in humans, the major biliary fluoropyrimidine metabolites are conjugates of FBAL and bile acids.
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iScience
February 2025
Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA.
The vagus nerve is proposed to enable communication between the gut microbiome and the brain, but activity-based evidence is lacking. We find that mice reared germ-free exhibit decreased vagal tone relative to colonized controls, which is reversed via microbiota restoration. Perfusing antibiotics into the small intestines of conventional mice, but not germ-free mice, acutely decreases vagal activity which is restored upon re-perfusion with intestinal filtrates from conventional, but not germ-free, mice.
View Article and Find Full Text PDFJ Gastrointest Cancer
January 2025
Department of Clinical Laboratory, Shandong Provincial Third Hospital, Shandong University, Jinan, Shandong, China.
Purpose: Liquid biopsy technology has received widespread attention in the early diagnosis of cholangiocarcinoma (CCA).
Methods: We collected bile samples from 48 patients with CCA and 48 patients with gallstones at Shandong Provincial third Hospital. We quantified bile circulating free DNA (cfDNA) of syncytin-1 and SLC7A11, calculated the correlation between syncytin-1 and SLC7A11 expression and clinical parameters by Spearman rank correlation, plotted Receiver Operating Characteristic (ROC) curves, and compared the Area Under Curve (AUC) values to explored early diagnostic utility in patients.
Mol Genet Metab
January 2025
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA. Electronic address:
Cerebrotendinous Xanthomatosis (CTX) is a treatable, inborn error of bile acids metabolism caused by pathogenic variants in CYP27A1. CTX is a multi-organ system disorder that progresses over decades. Clinical features include cerebellar dysfunction, pyramidal tract dysfunction, cognitive deficits and decline, peripheral neuropathy, chronic diarrhea, bilateral cataracts, and tendon xanthomas.
View Article and Find Full Text PDFMol Divers
January 2025
Department of Biophysics, Panjab University, Chandigarh, 160014, India.
Alzheimer's disease (AD) is a degenerative neurological disorder defined by the formation of β-amyloid (Aβ) plaques and neurofibrillary tangles within the brain. Current pharmacological treatments for AD only provide symptomatic relief, and there is a lack of definitive disease-modifying therapies. Chemical chaperones, such as 4-Phenylbutyric acid (4PBA) and Tauroursodeoxycholic acid, have shown neuroprotective effects in animal and cell culture models.
View Article and Find Full Text PDFLife Metab
October 2024
Laboratory of Metabolic Signaling, Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
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