Search results for "ENTEROHEPATIC CIRCULATION"
showing 8 items of 8 documents
Infant Formula Feeding Increases Hepatic Cholesterol 7α Hydroxylase (CYP7A1) Expression and Fecal Bile Acid Loss in Neonatal Piglets.
2018
BACKGROUND: During the postnatal feeding period, formula-fed infants have higher cholesterol synthesis rates and lower circulating cholesterol concentrations than their breastfed counterparts. Although this disparity has been attributed to the uniformly low dietary cholesterol content of typical infant formulas, little is known of the underlying mechanisms associated with this altered cholesterol metabolism phenotype. OBJECTIVE: We aimed to determine the molecular etiology of diet-associated changes in early-life cholesterol metabolism with the use of a postnatal piglet feeding model. METHODS: Two-day-old male and female White-Dutch Landrace piglets were fed either sow milk (Sow group) or d…
Interruption of the enterohepatic circulation of phenprocoumon by cholestyramine
1977
The effect of cholestyramine (12 gm/day divided into 3 doses) on the pharmacokinetics and pharmacodynamics of a single intravenouse dose (30 mg) of phenprocoumon was studied in 6 normal subjects. Cholestyramine treatment led to an increase in the rate of elimination of phenprocoumon in all. Total clearance increased 1.5- to 2-fold. The total anticoagulant effect per dose was considerably reduced during treatment with cholestyramine. Binding studies in vitro showed that phenprocoumon is strongly bound to cholestyramine and that at a given cholestyramine concentration the percentage of phenprocoumon bound remained constant over a large concentration range of phenprocoumon. The results suggest…
CLA-Enriched Diet Containing t10,c12-CLA Alters Bile Acid Homeostasis and Increases the Risk of Cholelithiasis in Mice
2011
International audience; Mice fed a mixture of CLA containing t10,c12-CLA lose fat mass and develop hyperinsulinemia and hepatic steatosis due to an accumulation of TG and cholesterol. Because cholesterol is the precursor in bile acid (BA) synthesis, we investigated whether t10,c12-CLA alters BA metabolism. In Expt. 1, female C57Bl/6J mice were fed a standard diet for 28 d supplemented with a CLA mixture (1 g/100 g) or not (controls). In Expt. 2, the feeding period was reduced to 4, 6, and 10 d. In Expt. 3, mice were fed a diet supplemented with linoleic acid, c9,t11-CLA, or t10,c12-CLA (0.4 g/100 g) for 28 d. In Expt. 1, the BA pool size was greater in CLA-fed mice than in controls and the …
Pharmacokinetics and bioavailability of diclofenac in the rat.
1991
Diclofenac sodium is a widely used drug with interesting absorption and disposition features when administered to laboratory animals. The present study was undertaken to assess the pharmacokinetics of the drug after iv and gastrointestinal dosing to rats. Renal excretion of unchanged drug was negligible, but biliary excretion of the drug (unchanged and conjugated) was detected in bile duct-cannulated rats; it accounted for 27.2 and 31.2% of the total dose following iv and intraduodenal administration, respectively. Most of the drug excreted in the bile was conjugated diclofenac; unchanged drug accounted for only 4.7 and 5.4% of total diclofenac excreted in the bile after iv and intraduodena…
A Model‐Based Workflow to Benchmark the Clinical Cholestasis Risk of Drugs
2021
We present a generic workflow combining physiology-based computational modeling and in vitro data to assess the clinical cholestatic risk of different drugs systematically. Changes in expression levels of genes involved in the enterohepatic circulation of bile acids were obtained from an in vitro assay mimicking 14 days of repeated drug administration for 10 marketed drugs. These changes in gene expression over time were contextualized in a physiology-based bile acid model of glycochenodeoxycholic acid. The simulated drug-induced response in bile acid concentrations was then scaled with the applied drug doses to calculate the cholestatic potential for each compound. A ranking of the cholest…
A Physiology-Based Model of Human Bile Acid Metabolism for Predicting Bile Acid Tissue Levels After Drug Administration in Healthy Subjects and BRIC …
2019
Drug-induced liver injury (DILI) is a matter of concern in the course of drug development and patient safety, often leading to discontinuation of drug-development programs or early withdrawal of drugs from market. Hepatocellular toxicity or impairment of bile acid (BA) metabolism, known as cholestasis, are the two clinical forms of DILI. Whole-body physiology-based modelling allows a mechanistic investigation of the physiological processes leading to cholestasis in man. Objectives of the present study were: (1) the development of a physiology-based model of the human BA metabolism, (2) population-based model validation and characterisation, and (3) the prediction and quantification of alter…
Pharmacokinetics, bioavailability and absorption of flumequine in the rat.
1999
Abstract The study demonstrates that the oral extent of bioavailability of flumequine in the rat, relative to the intravenous injection, is complete (0.94±0.04) and not significantly different from that found by the intraduodenal route (0.95±0.04). The rate of oral bioavailability, however, is slow ( k a =1.20±0.07 h −1 ; T max =2.0 h), but enough to maintain plasma levels above the minimal inhibitory concentration of the most common pathogens for an extended period of time (about 10 h). The reason for the oral absorption slowness could be a slow gastric emptying, an adsorption to the gastric mucosae, a precipitation in the gastric medium or any other feature concerning the stomach as the i…
Synthese, Verteilung und Ausscheidung von 14C markiertem 2-Phenyl-3-methyl-tetrahydro-1,4-oxazin (Preludin)
1958
A radioactive preludin preparation, C14 labelled on the 2-carbon of the tetrahydrooxazine ring, was injected into mice in doses of 100 mg/kg s.c. and rats in doses of 10 mg/kg i.v. The radioactivity of the tissues and excreta was followed for 48 hours. An activity concentration surpassing the average body concentration was obtained for a short time in the lungs and for a longer time in kidneys, liver and in the wall of stomach and small intestine. 95–99% of the total activity is found in the urine. The kidney excretion is virtually finished at the end of 8 hours; 1–5% appear after the 8th hour in faeces. No radioactivity was obtained from the expired CO2. The main excretion organs are kidne…