Expression of the insulin-regulatable transporter GLUT-4 in muscle is influenced by neurogenic factors.
To investigate whether the expression of GLUT-4 is influenced by neurogenic factor(s) released from the nerve to the muscle, we measured GLUT-4 at different time points after sectioning the sciatic nerve at different locations in two groups of rats. Specifically, GLUT-4 was measured at 12, 24, and 48 h after severing the sciatic nerve. In one group of animals the muscles were left either with a short nerve stump attached to the muscle, or, in another group of animals, a long nerve stump remained attached to the muscle. In both groups of animals the contralateral limb served as a control. We examined GLUT-4 in the red (RG) and white gastrocnemius (WG), since the RG is highly responsive to denervation and the WG is quite resistant to denervation [L. A. Megeney, P.D. Neufer, G. L. Dohm, M. H. Tan, C. A. Blewtt, G. C. B. Elder, and A. Bonen. Am. J. Physiol. 264 (Endocrinol. Metab. 27): E583-E593, 1993]. In the long nerve stump WG no change in GLUT-4 was observed at 12, 24, or 48 h after denervation (P > 0.05). In the short nerve stump WG, changes were not evident at 12 and 24 h (P > 0.05), but by 48 h a significant decrement (-12.7 +/- 6.7%) was observed (P < 0.05). GLUT-4 changes were only evident 48 h after denervation (-19.8 +/- 4.5%; P < 0.05) in the long nerve stump RG.(ABSTRACT TRUNCATED AT 250 WORDS)
Megeney
L A
LA
Department of Kinesiology, University of Waterloo, Ontario, Canada.
Prasad
M A
MA
Tan
M H
MH
Bonen
A
A
D000818:Animals; D015153:Blotting, Western; D015870:Gene Expression / Q000502:physiology*; D051275:Glucose Transporter Type 4; D007328:Insulin / Q000502:physiology*; D007700:Kinetics; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000302:isolation & purification; D009121:Muscle Denervation; D009124:Muscle Proteins; D009132:Muscles / Q000294:innervation* / Q000378:metabolism*; D009928:Organ Specificity; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D012584:Sciatic Nerve / Q000502:physiology*; D013997:Time Factors
D051275:Glucose Transporter Type 4; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; C495694:Slc2a4 protein, rat