The uptake of 3-deoxy-3-fluoro-D-Glucose by synaptosomes from rat brain cortex

✍ Scribed by D. M. Halton; N. F. Taylor; D. P. Lopes

• Publisher: John Wiley and Sons
• Year: 1980
• Tongue: English
• Weight: 661 KB
• Volume: 5
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/jnr.490050309

✦ Synopsis

Abstract

D‐[3‐^3^H]‐3‐deoxy‐3‐fluoroglucose was synthesized chemically and shown to be transported into rat brain synaptosomes by a saturable process with a K~m~ 6.2 × 10^−4^ M and a V~max~ 2.8 nmole · mg protein^−1^. After an initial, rapid period of transport, further uptake of the fluorosugar is restricted by the rate of its phosphorylation. Both D‐glucose and cytochalasin B are competitive inhibitors of 3‐deoxy‐3‐fluoro‐D‐glucose transport with K~i~ values of 93 μm and 6.0 × 10^−7^ M, respectively. Phloretin, N‐ethylmaleimide and p‐chloromercuribenzoate also inhibit the fluorosugar uptake, whereas ouabain and changes in K^+^, Na^+^, Mg^2+^ and Ca^2+^ ions have only a small effect. The recorded 3‐deoxy‐3‐fluoro‐D‐glucose influx is slightly reduced by potassium cyanide, antimycin A, 2,4‐dinitrophenol, and rotenone. The uptake reduction caused by these four reagents is relieved by the addition of exogenous ATP. The possible influence of hexokinase activity on the uptake process is discussed.