Measurement of ileal amino acids (AA) bioavailability is recommended to evaluate protein quality. A dual isotope tracer method, based on plasma isotopic enrichment ratios, has been proposed to determine true digestibility in humans. In a pilot study, we aimed to evaluate whether this method could be implemented in rats to determine AA bioavailability based on isotopic enrichment ratios measured in cecal digesta or plasma samples. Goat milk proteins were intrinsically labeled with N and H. Wistar rats were fed a meal containing the doubly labeled goat whey proteins and a tracer dose of C-spirulina. Blood samples were collected 0, 1 h and 3 h after meal ingestion from the tail vein. The rats were euthanized 4 h (n = 6) or 6 h (n = 6) after meal to collect plasma and intestinal contents. True orocecal protein digestibility and AA bioavailability were assessed by means of N and H enrichment in cecum content and compared with absorption indexes determined at the plasma or cecum level using isotopic ratios. Plasma kinetics of isotopic enrichment could not be completed due to the limited quantity of plasma obtained with sequential blood collection. However, the absorption indexes determined from cecal N or H/C ratios gave coherent values with true orocecal AA bioavailability. This dual isotope approach with measurements of isotopic ratios in digestive content could be an interesting strategy to determine true AA bioavailability in ileal digesta of rats.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1007/s00726-022-03137-5 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Insights into the separation, enantioseparation and recognition mechanisms of methamphetamine isotopologues on achiral and polysaccharide-based chiral columns in high-performance liquid chromatography.
Anal Chim Acta
February 2025
Institute of Physical and Analytical Chemistry, School of Exact and Natural Sciences, Tbilisi State University, 0179, Tbilisi, Georgia. Electronic address:
Background: Isotopologues resulting from the labelling of molecules with deuterium have attracted interest due to the isotope effect observed in chemistry and biosciences. Isotope effect may also play out in noncovalent interactions and mechanisms leading to intermolecular recognition. In chromatography, differences in retention time between isotopologues, as well as between isotopomers have been observed resulting in two different elution sequences (isotope effects): the normal isotope effect when heavier isotopologues retain longer than lighter analogues, and the inverse isotope effect featuring the opposite elution order.
View Article and Find Full Text PDFSclerostin and OPG/RANK-L system take part in bone remodeling in patients with acromegaly.
Front Endocrinol (Lausanne)
January 2025
Department and Clinic of Endocrinology, Diabetes and Isotope Therapy, Wroclaw Medical University, Wrocław, Poland.
Article Synopsis
- Acromegaly is marked by increased bone turnover and higher vertebral fracture risk, with sclerostin inhibiting bone formation and playing a role in the OPG/RANK-L system that regulates bone metabolism.
- The study investigated levels of sclerostin, osteoprotegerin (OPG), and RANK-L in 126 patients with varying acromegaly activity, aiming to explore connections between sclerostin and bone health.
- Results showed lower sclerostin levels in acromegaly patients compared to controls, with notable differences in OPG levels across groups but no significant changes in RANK-L; a positive correlation was found between sclerostin and OPG in patients with various acromegaly
An Evaluation of 90Y Bremsstrahlung SPECT Image Quality in the Presence of 99mTc: A Technical Perspective on Same-Day Radioembolization.
Curr Oncol
November 2024
Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands.
In same-day radioembolization, 99mTc-MAA SPECT/CT, 90Y radioembolization, and post-treatment 90Y SPECT/CT procedures are conducted on the same-day, resulting in a dual-isotope environment of 90Y and 99mTc during post-treatment imaging. This study aimed to quantify the impact of 99mTc on 90Y bremsstrahlung-SPECT/CT image quality and to establish an optimised imaging protocol for both clinical practice, and with advanced reconstruction techniques. Utilising a NEMA IQ phantom, contrast recovery coefficients (CRCs) were measured to evaluate the 90Y image quality degradation caused by 99mTc.
View Article and Find Full Text PDFInsights from multiple stable isotopes (C, N, Cl) into the photodegradation of herbicides atrazine and metolachlor.
Chemosphere
February 2025
Département des sciences de la Terre et de l'atmosphère, Université du Québec à Montréal, Montréal, QC, H2X 1Y4, Canada; Geotop Research Centre, Montréal, QC, H2X 3Y7, Canada. Electronic address:
Many processes can contribute to the attenuation of the frequently detected and toxic herbicides atrazine and metolachlor in surface water, including photodegradation. Multi-element compound-specific isotope analysis has the potential to decipher between these different degradation pathways as Cl is a promising tool for both pathway identification and a sensitive indicator of degradation for both atrazine and metolachlor. In this study, photodegradation experiments of atrazine and metolachlor were conducted under simulated sunlight in buffered solutions (direct photodegradation) and with nitrate (indirect photodegradation by OH radicals) to determine kinetics, transformation products and isotope fractionation for C, N and for the first time Cl.
View Article and Find Full Text PDFReliable and precise Zn isotopic analysis of biological matrices using a fully automated dual-column purification procedure.
Anal Bioanal Chem
December 2024
Department of Physics and Astronomy, University of Calgary, 2500 University Dr. NW, Calgary, AB, T2N 1N4, Canada.
A fully automated dual-column purification procedure for Zn from biological samples, designed for subsequent Zn isotopic analysis, is presented that utilizes the prepFAST MC™ system (Elemental Scientific), DGA resin (TrisKem International), and TK201 resin (TrisKem International). The procedure developed enables the unattended processing of 20 samples per day and is characterized by low and reproduceable blanks (< 1.5 ng), no carry-over or memory effect, high reusability (> 50 times), high Zn yields 100.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!