Glucose transporter localization in rat skeletal muscle. Autoradiographic study using ATB-[2-3H]BMPA photolabel.
Surface glucose transporters of intact muscles were photolabeled with the membrane impermeant ATB-[2-3H]BMPA reagent and localized by autoradiography. We found sparse labeling of the glucose transporters by ATB-[2-3H]BMPA on the sarcolemmal membrane around the muscle fiber. The majority of label was on the interior of the muscle fiber, at a discrete site which matched the distribution of AI junctions and which was presumed to be on the exterior surface of T-tubules. The amount of photolabel on the T-tubule was increased in response to insulin and was blocked by cytochalasin B. These results support the concept that glucose transport may occur predominantly across the T-tubule membrane under basal and insulin-stimulated conditions.
Dudek
R W
RW
Department of Cell Biology, School of Medicine, East Carolina University, Greenville, NC 27858.
Dohm
G L
GL
Holman
G D
GD
Cushman
S W
SW
Wilson
C M
CM
D000345:Affinity Labels; D000818:Animals; D001345:Autoradiography / Q000379:methods*; D001386:Azides; D003571:Cytochalasin B / Q000494:pharmacology; D004187:Disaccharides; D051275:Glucose Transporter Type 4; D006027:Glycosides; D007328:Insulin / Q000494:pharmacology; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000032:analysis*; D009124:Muscle Proteins; D009132:Muscles / Q000737:chemistry*; D010777:Photochemistry; D011437:Propylamines; D051381:Rats; D017207:Rats, Sprague-Dawley; D012508:Sarcolemma / Q000737:chemistry; D014316:Tritium
D000345:Affinity Labels; D001386:Azides; D004187:Disaccharides; D051275:Glucose Transporter Type 4; D006027:Glycosides; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D011437:Propylamines; C495694:Slc2a4 protein, rat; D014316:Tritium; C065412:2-N-(4-(1-azitrifluoroethyl)benzoyl)-1,3-bis-(mannos-4-yloxy)-2-propylamine; D003571:Cytochalasin B