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G Bories

Publications and source records attributed to G Bories.

At least 19 recordsLinked to original sources
PubMed1998

1,4-Dihydroxynonene mercapturic acid, the major end metabolite of exogenous 4-hydroxy-2-nonenal, is a physiological component of rat and human urine.

In the present study 1,4-dihydroxynonene mercapturic acid (DHN-MA), previously shown to be the major urinary metabolite of 4-hydroxy-2-nonenal (HNE) administered to the rat, was characterized and determined to be a normal constituent of rat and human urine. DHN-MA was excreted as a mixture of at least two stereoisomers as determined by ion trap LC-MS/MS/MS after solid-phase extraction and HPLC purification. The 24-h urinary excretion of this compound was about 10 ng and 5 microg for rat and human, respectively. This end metabolite of the lipid peroxidation product HNE could represent a specific and noninvasive biomarker.

Adult↗
PubMed1998

Identification of novel urinary metabolites of the lipid peroxidation product 4-hydroxy-2-nonenal in rats.

Following iv administration of 4-hydroxy-2-nonenal (HNE) and [4-3H]HNE to rats, 15 polar urinary metabolites accounting for about 50% of the urinary radioactivity were separated by HPLC. Among them, eight major compounds and tritiated water were quantified. The metabolites were unequivocally characterized using GC/MS and ESI/MS/MS/MS. Most of "HNE polar metabolites" originate from omega-oxidation of 4-hydroxy-2-nonenoic acid (HNA): 9-hydroxy-HNA, its mercapturic acid conjugate, and two diastereoisomers of the corresponding lactone. The oxidation of 9-hydroxy-HNA by alcohol and aldehyde dehydrogenases leads to the excretion of 9-carboxy-HNA and of the corresponding lactone mercapturic acid conjugate. 1, 4-Dihydroxy-2-nonene (DHN) originating from the reduction of HNE by alcohol dehydrogenase was to a lesser extent omega-hydroxylated, leading to 9-hydroxy-DHN which was excreted as a mercapturic acid conjugate (two diastereoisomers).

Aldehydes↗
PubMed1998

Metabolism of clenbuterol in rats.

The metabolic fate of [14C]clenbuterol was studied in male and female Wistar rats. After a single oral dose of 200 microgram/kg [14C]clenbuterol, in an 8-day study period, approximately 60% of the radioactivity was eliminated in urine; 20 and 30% of the radioactivity was excreted in feces by male and female rats, respectively. HPLC coupled to on-line radioactivity detection allowed the separation and quantitation of clenbuterol metabolites, some of which were found to be poorly stable in urine. Most of the urinary and fecal metabolites of clenbuterol were isolated and identified using various MS techniques. Analytical methods were also developed to establish the metabolic profiles in feces and tissues, up to 72 hr after clenbuterol administration. Clenbuterol was mainly metabolized by N-dealkylation (secondary amine), as well as N-oxidation and sulfate conjugation (primary amine). Gender-related differences in the rates of clenbuterol N-dealkylation were observed. 4-N-Hydroxylamine was the major metabolite detected in urine, whereas more than one half of the radioactivity in feces was associated with clenbuterol sulfamate.

Adrenergic beta-Agonists↗
PubMed1997

Evidence for a new and major metabolic pathway clenbuterol involving in vivo formation of an N-hydroxyarylamine.

Clenbuterol is a beta-adrenergic agonist widely but illegally used in cattle as a growth promoter. The metabolic fate of this drug remains unknown in the main target species, i.e. the bovine, and only limited data have been published concerning its biotransformations in laboratory animals. A metabolic study has been carried out in the rat using 3H- and 14C-labeled clenbuterol. Urine appeared to be the major excretion pathway. Using a soft technique for urine preparation, extraction, and purification, as well as adequate analytical tools in order to preserve labile metabolites, N-oxidation products of the parental drug on the primary amine function were identified for the first time. Clenbuterol hydroxylamine was the major compound, but 4-nitroclenbuterol was also detected. The metabolic pathway leading to the formation of clenbuterol hydroxylamine prevails at high dosages. Clenbuterol hydroxylamine (but not 4-nitroclenbuterol) was also formed extensively when the drug was incubated with rat liver microsomal fractions in aerobic conditions. It is concluded that oxido reduction during urine preparation have previously impaired the identification of this toxicologically important clenbuterol metabolic route.

Administration, Oral↗
PubMed1992

[Current trends in the field of animal husbandry].

The progress achieved over the past 30 years in the areas of nutrition, physiology, genetics and prophylaxis has lead to the intensification of animal production. Feed additives have been one of the factors involved in this evolution often wrongly accused of being at the origin of a so-say degradation of the quality of the products. Where nutritional quality is concerned, it must be observed that the genetic determinism and the homeostasis of the organisms maintain practically constant the proportions of the elementary constituents (amino acids, fatty acids) and the composition of the basic components (proteins, phospholipids) of the living matter. However, the relative proportions of these components (proteins/lipids) can be modified by genetic and nutritional factors. If the quantitative modifications of composition are easily balanced by the diversity of the human diet, they can heavily influence the technological and organoleptic properties of the individual animal products. The on-going evolution, namely the incidence of the new biotechnologies, should not modify this situation, if only to lead to the production of animals whose tissue and product composition would be adapted to the technological and dietetics demand. The nutritional balance should then be assumed by a better educated and informed consumer.

Animal Husbandry↗
PubMed1989

Profiling of free and conjugated [3H]zeranol metabolites in pig plasma.

Extraction and high-performance liquid chromatographic (HPLC) procedures are described that permit the complete analysis of free and conjugated zeranol metabolites in plasma from pigs implanted with [3H]zeranol. Free metabolites (9.0%) are extracted and then analysed by radio-HPLC on a reversed phase C18 column. They are distributed between three compounds that have been identified by gas chromatography-mass spectrometry as taleranol, zeranol and zeralanone. Direct radio-HPLC of the pre-extracted, deproteinated and Sep-Pak C18-purified plasma on a reversed-phase C18 column using tetrabutylammonium as an ion-pairing agent showed four main peaks: one corresponds to a weakly retained unidentified compound(s) (20%) and the other three were identified as the taleranol, zeranol and zeralanone glucuro conjugates. However, the total recovery is only about 25% owing to strong affinity of this polar material for the plasma proteins. Enzymatic deconjugation of the pre-extracted plasma followed by radio-HPLC analysis of the freed metabolites led to a good recovery of the radioactivity (81.8%) and allowed the quantitation of the different metabolites. These preliminary results indicate that zeranol is metabolized in the pig following pathways similar to those in other tested species.

Animals↗
PubMed1987

Simple gas chromatographic method for the determination of medicagenic acid in alfalfa (Medicago sativa).

A gas chromatographic method for the determination of medicagenic acid in alfalfa leaves, stems, entire plant (tops) and roots and also in leaf protein concentrates is described. The method is based on extraction of lucerne saponins followed by hydrolysis of the triterpene glycosides. After derivatization of the liberated sapogenins to silylated products, the trimethylsilylated medicagenic acid was determined by gas chromatography. The sensitivity of the method permits the detection of 50 ng of medicagenic acid.

Chromatography, Gas↗
PubMed1984

Growth reduction in trout induced by naphthenic and isoprenoid hydrocarbons (Dodecylcyclohexane and pristane).

Rainbow trout were fed a diet containing 1% dodecylcyclohexane or pristane for 9 weeks. Feed intake was recorded daily and weight gain every 3 weeks. These animals were compared with fish receiving a hydrocarbon-free diet (groups fed ad libitum and pair-fed groups for which the ration provided was the amount of food consumed by the hydrocarbon-contaminated fish, the day before). The total food ingested by the pristane and dodecylcyclohexane groups amounted to 66 and 70%, respectively, of that eaten by the controls. The final mean weight of the controls was twofold their initial weight. The average weight gain of the dodecylcyclohexane and pristane groups was 37 and 25%. During the same period the fish of the pair-fed groups gained approximately 70% of their initial weight. Significant effects of hydrocarbon consumption on food conversion factors, viscerosomatic index, hepatosomatic index, and liver lipid concentration were observed. The results are discussed in relation to the possible causes of such changes.

Animals↗
PubMed1979

Electron-capture detection of chloramphenicol using a heptafluorobutyrate derivative. Application to residues in milk.

A gas-liquid chromatographic method is described for the quantitation of the halogenated heptafluorobutyrate derivative of chloramphenicol, using electron-capture detection. Treatment of the chromatographic support with heptafluorobutyric anhydride permits a linear recovery even at very low concentrations. After extraction using acetonitrile followed by a convenient cleaning procedure, this method can be applied to the determination of trace amounts of chloramphenicol in milk. Interfering peaks have been observed on the chromatograms of some control milk samples. These determine the detection limit of 50 ppb.

Animals↗
PubMed1978

[Survey of contamination of food by 3, 4-benzopyrene. I. Demonstration of a universal method of determination. Application to the determination in complete meals in food emporia].

A versatile spectrofluorimetric method is proposed for the determination of 3,4-benzopyrene in foods and biological material. Recording the emission spectrum allows a reliable identification, and determination at a 0,2 ppb level, with 85 p. 100 recovery and good reproductibility. The time required for analysis is decreased, if compared to existing methods. As a test of its reliability, results of a survey on 3,4-benzopyrene content in canteen meals are presented. The values obtain are very low, generally below 1 ppb; their significance is discussed.

Animals↗
PubMed1975

[The effect of prolonged injestion of paraffin oil in pigs: selective retention and interference with cholesterol metabolism].

Hydrocarbons administered to the pig as paraffin oil fix preferentially in the liver, and the existence of a selective filtration mechanism can be supposed. Moreover a significant increase of the level of squalene is observed in adipose tissue and liver; it could correspond to an inhibition of the cholesterol synthesis following vitamin A deficiency due to perturbation of intestinal absorption.

Adipose Tissue↗
PubMed1975

[Metabolism of paraffinic and naphthalenic hydrocarbons in higher animals. I. Retention of paraffins (normal, cyclo and branched) in rats].

Apparent retention of aliphatic hydrocarbons in the Rat is studied. Animals weighing 150 g are put into metabolism cages and given a 15 mg dose of one of the paraffins studied in solution in the peanut oil of the ration. There is no urinary excretion, and fecal elimination is low (5-10%), as long as the carbon chain stays below 24 atoms. Real retention is measured on animals recieving a single dose of 15 mg in the same conditions. Branched paraffins give only very low residual amounts 15 days after ingestion, while n-paraffins and cyclo-paraffins remain unchanged in the carcass, as long as the number of carbon atoms is not greater than 20; the proportion of the latter paraffins is about 8% of the dose ingested (5 days as 21 days after intake). Beyond C 20, real retention decreases rapidly to zero.

Alkanes↗