Search results for "metabolite"
showing 10 items of 551 documents
Evidence that 3 alpha-hydroxy-5 alpha-pregnan-20-one is a physiologically relevant modulator of GABA-ergic neurotransmission.
1991
Abstract 3α-Hydroxy-5α-pregnan-20-one (HPO) is a progesterone metabolite which exhibits narcotic properties at high concentrations by interactions with the receptor for gamma-aminobutyric acid (GABA). The present investigation characterized low-dose effects of HPO on GABA A receptor binding, by determining the allosteric properties of HPO on the in vitro binding of 3 H-muscimol to membrane fractions from the cerebella of ovariectomized rats. A newly developed method for tissue preparation was used to wash out endogenous ligands interfering with the assay. HPO reduced the affinity of 3 H-muscimol to GABA A receptor sites by 52% and enhanced the number of accessible binding sites from 5.5±0.5…
Carbamazepine exposure in the sea anemones Anemonia sulcata and Actinia equina: Metabolite identification and physiological responses
2020
Trabajo presentado en el 11º Congreso Ibérico, 8º Iberoamericano de Contaminación y Toxicología (CICTA 2018) celebrado en la Escuela Técnica Superior de Ingeniería de Montes, Forestal y del Medio Natural, Madrid del 11 al 13 de julio de 2018
Biomonitoring of glyphosate and AMPA in the urine of Spanish lactating mothers
2021
The objectives of this study were to evaluate the urinary levels of Glyphosate (Gly) and its metabolite aminomethylphosphonic acid (AMPA) in Spanish breastfeeding mothers (n = 97), to identify the main predictors of exposure and to perform a risk assessment. Urine samples were analyzed using a method based on solid phase extraction and liquid chromatography tandem mass spectrometry (LC-MS/MS) determination. The developed method showed limits of quantification of 0.1 μg/L for both analytes. The detection frequencies (DFs) were 54% for Gly and 60% for AMPA, with geometric means (GMs) of 0.12 μg/L and 0.14 μg/L, respectively. In the statistical analysis, no relationship was found between the u…
The use of fish bile metabolite analyses as exposure biomarkers to pulp and paper mill effluents
1998
The exposure of caged one-year-old whitefish (Coregonus lavaretus) to wood extractives and chlorophenolics from pulp and paper mill effluents in Lake Saimaa (SE Finland) was investigated. Whitefish were exposed at 17 locations affected by effluents from pulp and paper mills and at 5 reference areas. Resin and fatty acids and chlorophenolics in bile were analysed by GC and GC-MS. Cholesterol concentration in bile was also measured. Results show that despite of process changes to ECF and waste water treatment improvements employed by the pulp and paper industry in the study area, it is still possible to detect elevated concentrations of these substances in the bile of fish exposed in the vici…
Characterization of an isoproturon mineralizing bacterial culture enriched from a French agricultural soil.
2009
The phenylurea herbicide isoproturon, 3-(4-isopropylphenyl)-1,1-dimethylurea (IPU), was found to be rapidly mineralized by a bacterial culture isolated from an agricultural soil regularly exposed to IPU. Molecular analysis of the bacterial culture by DNA fingerprinting, cloning and sequencing of the 16S rRNA genes revealed that it consisted of six different members among whom the dominant was related to Sphingomonas sp. Six bacterial strains belonging to genera Ancylobacter, Pseudomonas, Stenotrophomonas, Methylobacterium, Variovorax and Agrobacterium were isolated from the IPU-degrading culture. None of these were able to degrade IPU in pure culture and only the intact culture sustained th…
A preliminary study on the distribution of morphine and its glucuronides in the subcompartments of blood.
1998
[Abstract ] The distribution of morphine, morphine-3-glucuronide (M3G), and morphine-6-glucuronide (M6G) in whole blood, plasma, and packed erythrocytes was studied. Parameters investigated were the hematocrit values (10, 42, 44, and 71%) and the water content of the samples. The blood-to-plasma ratio of morphine concentrations was unaffected by variations in hematocrit and water content, whereas the corresponding ratios for M3G and M6G were strongly influenced. Ratios were 0.53 to 0.65 and 0.52 to 0.62 in specimens with average hematocrit values (42 and 44%, respectively), and the ratios were 0.81 or 0.89 (hematocrit 10%) and 0.27 or 0.28 (hemalocrit 71%) in blood samples with different he…
SY26-2ACETALDEHYDE ENDOCANNABINOIDS AND DOPAMINE: IS THIS –JUST- “A MENAGE A TROIS”?
2015
As ethanol, its first metabolite, acetaldehyde (ACD), enhances dopamine neurotransmission and exerts rewarding and motivational effects in animal models tailored for studying addictive-like behaviours. The endocannabinoid system fine-tuning dopamine cell activity, affects distinct drug-related behaviours and specific drug-induced effects. In light of this, it becomes urgent to investigate the implications of …
Robust Conditional Independence maps of single-voxel Magnetic Resonance Spectra to elucidate associations between brain tumours and metabolites.
2020
The aim of the paper is two-fold. First, we show that structure finding with the PC algorithm can be inherently unstable and requires further operational constraints in order to consistently obtain models that are faithful to the data. We propose a methodology to stabilise the structure finding process, minimising both false positive and false negative error rates. This is demonstrated with synthetic data. Second, to apply the proposed structure finding methodology to a data set comprising single-voxel Magnetic Resonance Spectra of normal brain and three classes of brain tumours, to elucidate the associations between brain tumour types and a range of observed metabolites that are known to b…
Dietary fish protein lowers blood pressure and alters tissue polyunsaturated fatty acid composition in spontaneously hypertensive rats.
2003
Abstract Objectives To investigate the effect of two types of dietary protein on blood pressure, liver fatty acid desaturation and composition, and urine 6-keto-prostaglandin-F (PGF1α) level, the metabolite of prostacyclin. Methods 5-wk-old spontaneously hypertensive rats were fed 20% casein or purified fish protein. The fat source was 5% ISIO oil, which contains 47.9% (ω-6) and 1.7% (ω-3) total polyunsaturated fatty acids. After 2 mo on the diet, systolic blood pressure was reduced with fish protein compared with casein (189.8 ± 10.5 versus 220.7 ± 8.7). Results Excretion of 6-keto-PGF1α in urine was negatively correlated with blood pressure. Liver cholesterol and phospholipid concentratio…
The Co‐mutational Spectrum Determines the Therapeutic Response in Murine FGFR2 Fusion‐Driven Cholangiocarcinoma
2021
Background and aims Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver cancer and a highly lethal malignancy. Chemotherapeutic options are limited, but a considerable subset of patients harbors genetic lesions for which targeted agents exist. Fibroblast growth factor receptor 2 (FGFR2) fusions belong to the most frequent and therapeutically relevant alterations in ICC, and the first FGFR inhibitor was recently approved for the treatment of patients with progressed, fusion-positive ICC. Response rates of up to 35% indicate that FGFR-targeted therapies are beneficial in many but not all patients. Thus far, no established biomarkers exist that predict resistance or r…