A substantial part of GLUT-1 in crude membranes from muscle originates from perineurial sheaths.
The distribution of GLUT-1 and GLUT-4 in cryosections of rat skeletal muscles was investigated immunocytochemically. Intense labeling of GLUT-1 was found in the perineurial sheaths of intramuscular nerves, whereas only a very faint signal was associated with the sarcolemma, and labeling of extraneural vessels was not detectable. The majority of the GLUT-4 reactivity was located at the periphery of muscle cells in nonuniform patches, and GLUT-4 was absent in vessels and nerves. In sections of femoral nerve GLUT-1 was confined to the perineurial sheath and endoneurial vessels. The contribution of GLUT-1 from intramuscular perineurial sheaths to total GLUT-1 in a muscle was determined from immunoblots of crude membranes isolated from mixtures of homogenates of excised nerves and muscles. The recovery of GLUT-1 increased linearly with the amount of nerve added, and it was calculated that GLUT-1 from intramuscular perineurial sheaths accounted for approximately 60% of the GLUT-1 content in a membrane fraction from soleus muscle or red gastrocnemius. The remaining 40% of GLUT-1 is likely to originate from the sarcolemma.
Handberg
A
A
Institute of Medical Physiology B, Panum Institute, University of Copenhagen, Denmark.
Kayser
L
L
Høyer
P E
PE
Vinten
J
J
D000818:Animals; D001808:Blood Vessels / Q000378:metabolism; D005267:Femoral Nerve / Q000098:blood supply / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D051272:Glucose Transporter Type 1; D007150:Immunohistochemistry; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D009132:Muscles / Q000294:innervation / Q000378:metabolism*; D009420:Nervous System / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D051272:Glucose Transporter Type 1; D009004:Monosaccharide Transport Proteins; C495679:Slc2a1 protein, rat