75,77Br- and 123I-analogues of D-glucose as potential tracers for glucose utilisation in heart and brain.
A number of D-glucose analogues labelled with either the positron emitter 75Br (T 1/2 = 1.6 h) or the single photon emitter 123I (T 1/2 = 13.3 h) were studied as potential tracers for glucose utilisation in heart and brain. Of these, 3-deoxy-3-bromo-D-glucose, 3-deoxy-3-iodo-D-glucose, methyl 2-deoxy-2-bromo-beta-D-glucoside and methyl 2-deoxy-2-iodo-beta-D-glucoside showed little uptake of radioactivity into brain and an unfavourable ratio of heart-to-blood and heart-to-lung concentrations. In contrast, methyl 3,4,6-tri-O-acetyl-2-deoxy-2-iodo-beta-D-glucoside (MTIG) and methyl 3,4,6-tri-O-acetyl-2-deoxy-2-bromo-beta-D-glucoside (MTBG) showed promising brain uptake (160% MBC for MTBG) with a good brain-to-blood concentration ratio of 0.8. MTBG is not metabolically altered in the brain. Thus, this compound may be a promising tracer for measuring glucose transport if it proves to be a substrate for the hexose carrier at the blood-brain-barrier.
D000818:Animals; D001812:Blood-Brain Barrier; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D001966:Bromine; D003837:Deoxy Sugars; D003847:Deoxyglucose / Q000031:analogs & derivatives*; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006321:Heart / Q000000981:diagnostic imaging; D007457:Iodine Radioisotopes; D051379:Mice; D008815:Mice, Inbred Strains; D009206:Myocardium / Q000378:metabolism*; D011868:Radioisotopes; D011877:Radionuclide Imaging
D003837:Deoxy Sugars; D007457:Iodine Radioisotopes; D011868:Radioisotopes; D003847:Deoxyglucose; D005947:Glucose; D001966:Bromine