Biomaterial Database

High-affinity choline uptake under various pH conditions: investigation of synaptosomal fluorescence. 1998

O V Chumakova, and I B Zavodnik

Institute of Biochemistry, Academy of Science of Belarus, Grodno.

The choline transport into synaptosomes obtained from the rat brain striatum was studied in the presence and absence of Na+ ions within the pH range 3.9-9.1. The intrinsic tryptophan fluorescence was investigated in synaptosomes at varying pH. Three pH ranges with different interpositions of the Na(+)-dependent and Na(+)-independent uptake curves were revealed: acid, alkaline, and weak-acid regions. It is assumed that pH 6-7 may be important in regulation of the cholinergic function because of the complicated interpositions of the two curves. The Km and Vmax values of both the Na(+)-dependent and Na(+)-independent processes for the striatal fraction were calculated using Lineweaver-Burk plots at three pH values. Some differences in the intrinsic tryptophan fluorescence of the synaptosomal membrane were observed in the presence and absence of Na+ ions in the pH range 6-7, but they were not statistically significant. At the variations of pH the alterations in the choline transport system did not correspond to the total structural changes in the synaptosomal membrane, when monitored by intrinsic tryptophan fluorescence. The pH-evoked choline transport changes may be due to specific alterations in the choline transport-related proteins.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D002794	Choline	A basic constituent of lecithin that is found in many plants and animal organs. It is important as a precursor of acetylcholine, as a methyl donor in various metabolic processes, and in lipid metabolism.	Bursine,Fagine,Vidine,2-Hydroxy-N,N,N-trimethylethanaminium,Choline Bitartrate,Choline Chloride,Choline Citrate,Choline Hydroxide,Choline O-Sulfate,Bitartrate, Choline,Chloride, Choline,Choline O Sulfate,Citrate, Choline,Hydroxide, Choline,O-Sulfate, Choline
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001693	Biological Transport, Active	The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.	Active Transport,Uphill Transport,Active Biological Transport,Biologic Transport, Active,Transport, Active Biological,Active Biologic Transport,Transport, Active,Transport, Active Biologic,Transport, Uphill
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23
D013050	Spectrometry, Fluorescence	Measurement of the intensity and quality of fluorescence.	Fluorescence Spectrophotometry,Fluorescence Spectroscopy,Spectrofluorometry,Fluorescence Spectrometry,Spectrophotometry, Fluorescence,Spectroscopy, Fluorescence
D013329	Structure-Activity Relationship	The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.	Relationship, Structure-Activity,Relationships, Structure-Activity,Structure Activity Relationship,Structure-Activity Relationships
D013574	Synaptosomes	Pinched-off nerve endings and their contents of vesicles and cytoplasm together with the attached subsynaptic area of the membrane of the post-synaptic cell. They are largely artificial structures produced by fractionation after selective centrifugation of nervous tissue homogenates.	Synaptosome