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UPTAKE OF α‐METHYL‐D‐GLUCOSIDE BY SYNAPTOSOMES FROM RAT BRAIN
Author(s) -
Warfield Anna S.,
Segal S.
Publication year - 1976
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1976.tb07018.x
Subject(s) - phloretin , phlorizin , chemistry , ficoll , galactose , differential centrifugation , biochemistry , sugar , synaptosome , substrate (aquarium) , chromatography , biophysics , glucose transporter , in vitro , biology , endocrinology , peripheral blood mononuclear cell , ecology , insulin
Influx of α‐methylglucoside into synaptosomes prepared by differential and Ficoll density gradient centrifugation was studied to determine whether this sugar could be used as a model for glucose transport in nerve endings. The rate of uptake of a‐methylglucoside was linear over a wide range of substrate concentrations. Influx was only slightly inhibited (12–15%) in the presence of glucose, 2‐deoxyglncose, phloretin and 2,4‐dinitrophenol and was unaffected by galactose or phlorizin. Conver‐ sion of a‐methylglucoside to phosphorylated intermediates in synaptosomes was negligible. The data are consislent with the influx of a‐methylglucoside being primarily a diffusion process or being mediated by a system with an extremely high K m . However, it is possible that a small portion of the sugar may be transported by the low affinity glucose transport system. The results indicate that a‐methylgluco‐ side is not a good model for glucose transport in synaptosomes as it is in other tissues.