title: Microautoradiographic studies of glucose uptake in skeletal muscle fibers at rest.
abstract: In the present study, differences in glucose uptake by muscle fibers in deep, middle, and superficial regions of the gastrocnemius were studied at rest by 2-deoxyglucose (2-DG) microautoradiography. Expression of the glucose transporter 4 (GLUT-4) protein, an isoform of the glucose transporter family, was analyzed as well. These data were compared with the activity of succinate dehydrogenase, a marker of oxidative metabolism, a-glycerophosphate dehydrogenase, an indicator of the glycolytic capacity, and myofibrillar ATPase. In the deep regions of the muscle, most fibers (86.9%) showed high 2-DG uptake and large amounts of GLUT-4 protein, whereas in the superficial regions, all fibers showed low 2-DG uptake and GLUT-4 expression. In the middle regions, fibers dominated (80.4%) showed low 2-DG uptake and small amounts of GLUT-4 protein. Analysis of metabolic properties revealed that most fibers in the deep region were oxidative and showed the highest 2-DG uptake; in the superficial region, the fibers were anaerobic and showed the lowest 2-DG uptake. In the middle region, most fibers were of the anaerobic and fast twitch type. It is concluded that 2-DG uptake correlates with GLUT-4 expression in the plasma membrane of type I and IIx fibers rather than with oxidative enzyme activity.
authors.affiliation: Department of Anatomy, Osaka Medical College, Takatsuki, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Hayasaki
authors.forename: M
authors.initials: M
authors.lastname: Shimada
authors.forename: K
authors.initials: K
authors.lastname: Kanbara
authors.forename: M
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D001345:Autoradiography / Q000379:methods; D001692:Biological Transport; D002250:Carbon Radioisotopes; D003847:Deoxyglucose / Q000493:pharmacokinetics; D005947:Glucose / Q000378:metabolism*; D051275:Glucose Transporter Type 4; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009004:Monosaccharide Transport Proteins / Q000378:metabolism; D018485:Muscle Fibers, Skeletal / Q000378:metabolism*; D009124:Muscle Proteins; D018482:Muscle, Skeletal / Q000378:metabolism*; D012680:Sensitivity and Specificity; D013385:Succinate Dehydrogenase / Q000378:metabolism
chemical_list: D002250:Carbon Radioisotopes; D051275:Glucose Transporter Type 4; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; C495693:Slc2a4 protein, mouse; D003847:Deoxyglucose; D013385:Succinate Dehydrogenase; D005947:Glucose