The D-glucose transporter is tissue-specific. Skeletal muscle and adipose tissue have a unique form of glucose transporter.
Using isotopic equilibration with [3H]D-glucose and measurement of D-glucose inhibitable cytochalasin B binding, I show that the erythrocytes of embryonic and newborn rats contain D-glucose transporters. On the basis of cytochalasin B binding and the time course of isotopic exchange, the number of transporters in rat embryonic erythrocytes is only 5% of that in human erythrocytes. Antibodies raised against the human erythrocyte glucose transporter were used as a probe to investigate the structural similarity between transporters. On this basis, the polypeptides of the glucose transporter of human erythrocytes and of embryonic rat erythrocytes are similar but not identical; in addition, certain antibodies showed similar reactivity toward the transporter of rat embryonic erythrocytes and that of rat brain. These antibodies, however, react with brain transporters 5 to 10 times better than with those of skeletal muscle and adipocytes suggesting that insulin responsive tissues may have a different type of glucose transporter. The cellular location of glucose transporters in skeletal muscle, determined by immunofluorescence, is on the plasma membrane or very close to the plasma membrane.
Wang
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Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138.
D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D000906:Antibodies; D003429:Cross Reactions; D003571:Cytochalasin B / Q000378:metabolism; D006801:Humans; D007163:Immunosorbent Techniques; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism*; D051381:Rats; D013379:Substrate Specificity
D000906:Antibodies; D009004:Monosaccharide Transport Proteins; D003571:Cytochalasin B