The nature of gamma-aminobutyric acid (GABA) transport has been investigated in preparations of rat brain synaptosomes using a number of thiol reagents with varying membrane permeabilities. N-Ethylmaleimide, p-chloromercuribenzoate and p-chloromercuriphenylsulfonate effectively inhibited GABA transport in both directions (i.e., uptake and release) whereas 5,5'-dithiobis-2-nitrobenzoate, mercaptopropionate and N- nitroethylenediamine were much less effective, or ineffective, even at millimolar concentrations. For each of the thiol reagents, the inhibition profile for GABA uptake was approximately the same as that for its release. The effectiveness of the reagents indicates that there is an external, reactable SH-group on the transporter, that the thiol reagent must be somewhat lipophilic for it to react with the SH-group(s), and that the same synaptosomal transport system is responsible for both uptake and release of GABA.
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http://dx.doi.org/10.1016/0014-5793(84)80509-8 | DOI Listing |
J Environ Sci (China)
July 2025
Department of Chemistry, Faculty of Science, University of Alberta, 11227 Saskatchewan Dr NW, Edmonton, Alberta, T6G 2G2, Canada; Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, 10-102 Clinical Sciences Building, Edmonton, Alberta, T6G 2G3, Canada. Electronic address:
Arsenic speciation in freshwater fish is crucial for providing meaningful consumption guidelines that allow the public to make informed decisions regarding its consumption. While marine fish have attracted much research interest due to their higher arsenic content, research on freshwater fish is limited due to the challenges in quantifying and identifying arsenic species present at trace levels. We describe here a sensitive method and its application to the quantification of arsenic species in freshwater fish.
View Article and Find Full Text PDFJ Environ Sci (China)
July 2025
Department of Chemistry, Faculty of Science, University of Alberta, 11227 Saskatchewan Dr NW, Edmonton, Alberta, T6G 2G2, Canada; Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, T6G 2G3, Canada. Electronic address:
We report here arsenic speciation in 1643 freshwater fish samples, representing 14 common fish species from 53 waterbodies in Alberta, Canada. Arsenic species were extracted from fish muscle tissue. Arsenic species in the extracts were separated using anion-exchange high-performance liquid chromatography (HPLC) and quantified using inductively coupled plasma mass spectrometry (ICPMS).
View Article and Find Full Text PDFJ Environ Sci (China)
July 2025
Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
Siderite tailings is a potentially cost-free iron (Fe) source for arsenic (As) fixation in hazardous arsenic-calcium residues (ACR) as stable scorodite. In this study, a pure siderite reagent was employed to investigate the mechanism and optimal conditions for As fixation in ACR via scorodite formation, while the waste siderite tailings were used to further demonstrate the cotreatment method. The cotreatment method starts with an introduction of sulfuric acid to the ACR for As extraction and gypsum precipitation, and is followed by the addition of HO to oxidize As(III) in the extraction solutions and finalized by adding siderite with continuous air injection for scorodite formation.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
School of Sciences and Humanities, Nazarbayev University, Astana 010000, Kazakhstan.
Doxorubicin (DOX) is one of the most widely used chemotherapy drugs in the treatment of both solid and liquid tumors in patients of all age groups. However, it is likely to produce several side effects that include doxorubicin cardiomyopathy. Nanoparticles (NPs) can offer targeted delivery and release of the drug, potentially increasing treatment efficiency and alleviating side effects.
View Article and Find Full Text PDFChemistry
January 2025
University of Padova: Universita degli Studi di Padova, Dipartimento di Scienze Chimiche, Via Marzolo 1, 35131, Padova, ITALY.
Chalcogenide exchange reactions are an important class of bimolecular nucleophilic substitution reactions (SN2) involving sulfur and selenium species as nucleophile, central atom, and/or leaving group, which are fundamental throughout redox biology and metabolism. While thiol-disulfide exchange reactions have been deeply investigated, those involving selenium are less understood, especially with regards to the polarised selenenyl sulfides RSe-SR' even though the directed reactivity of selenenyl sulfides is biologically crucial for selenoenzymes such as thioredoxin reductase (TrxR) and glutathione peroxidase (GPx). Synthetic methods to create asymmetric selenenyl sulfides with high regiochemical purity only emerged over the last five years; this functional group has already demonstrated powerful applications to cell biology, through probes for molecular imaging (e.
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