Biomaterial Database

On the significance of sialic acid in high affinity 5-hydroxytryptamine uptake by synaptosomes. 1978

G A Dette, and W Wesemann

Synaptosomes isolated from rat brain cortex incorporated [14C]5-hydroxytryptamine at 37 degrees C with high affinity. An apparent transport constant of Kt = 50nM was found. The high affinity uptake was decreased by treatment of synaptosomes with neuraminidase from Vibrio cholerae or Clostridium perfringens prior to incubation with [14C]5-hydroxytryptamine. The inhibition was related to the amount of sialic acid released, with a Ki value of 3.5 micrometer. A non-competitive type of inhibition was observed after treatment with neuraminidase. The inhibition caused by ouabain could not be enhanced by simultaneous treatment with neuraminidase. Neuraminidase did not lower the activity of (Na + K)-ATPase or Mg2-ATPase. These results suggest that sialic acid is involved in the 5-hydroxytryptamine uptake mechanism without functional linkage to the energy pump of the membrane, which maintains the sodium gradient necessary for 5-hydroxytryptamine transport.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D009439	Neuraminidase	An enzyme that catalyzes the hydrolysis of alpha-2,3, alpha-2,6-, and alpha-2,8-glycosidic linkages (at a decreasing rate, respectively) of terminal sialic residues in oligosaccharides, glycoproteins, glycolipids, colominic acid, and synthetic substrate. (From Enzyme Nomenclature, 1992)	Sialidase,Exo-alpha-Sialidase,N-Acylneuraminate Glycohydrolases,Oligosaccharide Sialidase,Exo alpha Sialidase,Glycohydrolases, N-Acylneuraminate,N Acylneuraminate Glycohydrolases,Sialidase, Oligosaccharide
D010042	Ouabain	A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.	Acocantherin,G-Strophanthin,Acolongifloroside K,G Strophanthin
D002540	Cerebral Cortex	The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulci. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.	Allocortex,Archipallium,Cortex Cerebri,Cortical Plate,Paleocortex,Periallocortex,Allocortices,Archipalliums,Cerebral Cortices,Cortex Cerebrus,Cortex, Cerebral,Cortical Plates,Paleocortices,Periallocortices,Plate, Cortical
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
D012701	Serotonin	A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.	5-HT,5-Hydroxytryptamine,3-(2-Aminoethyl)-1H-indol-5-ol,Enteramine,Hippophaine,Hydroxytryptamine,5 Hydroxytryptamine
D012794	Sialic Acids	A group of naturally occurring N-and O-acyl derivatives of the deoxyamino sugar neuraminic acid. They are ubiquitously distributed in many tissues.	N-Acetylneuraminic Acids,Acids, N-Acetylneuraminic,Acids, Sialic,N Acetylneuraminic Acids
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