Intact glucose transport system in denervated, morphologically
altered skeletal muscle from tetraplegic patients.
Aksnes, Anne-Kirsti, Nils Hjeltnes, Erica [diaeresis]odegaard
Wahlstr[diaeresis]om, Abram Katz, Juleen R Zierath, and Harriet
Wallberg-Henriksson.
Sunnaas Hospital, 1450 Nesoddtangen, Norway, and Department of
Clinical Physiology, Karolinska Institute, Karolinska Hospital, S-171
76 Stockholm, Sweden
APStracts 3:0101E, 1996.
The present study was undertaken to investigate the nature of the
whole body insulin resistance which characterizes patients with
complete cervical spinal cord lesion. Nine patients with C5-C7
lesions and ten age-matched healthy individuals were studied. Whole
body insulin mediated glucose utilization was reduced by 43% in the
tetraplegic patients compared to the controls (p<0.001). In the
tetraplegic patients, lean body mass corresponded to 66+/-3% of total
body mass. Despite whole body insulin resistance, in isolated vastus
lateralis muscle, basal and insulin-stimulated 3-0-methylglucose
transport, as well as protein expression of the insulin/exercise
regulatable glucose transporter, GLUT4, and glycogen content were
comparable between the patients and controls. Strikingly, muscle
fiber area was reduced by 44% (p<0.05), percentage of type IIb
fibers was increased (p<0.01) and there was a complete loss of
type I fibers in the patients. In conclusion, the dissociation
between whole body insulin-mediated glucose uptake and skeletal
muscle glucose transport in tetraplegic patients primarily reflects
the decreased muscle mass. Furthermore, these findings demonstrate a
remarkable capacity of skeletal muscle to maintain an intact glucose
transport system despite severe morphological alterations.
Received 28 November 1995; accepted in final form 6 May 1996.
APS Manuscript Number E562-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 28 May 96