Extracellular glucose distribution is not altered by insulin:
analysis of plasma and interstitial l-glucose kinetics.
Steil, Garry M., Joyce Richey, Jason K. Kim, Jae K. Wi, Kerstin
Rebrin, Richard N. Bergman, and Jang H. Youn.
Department of Physiology and Biophysics, University of Southern
California School of Medicine, Los Angeles, CA 90033
APStracts 3:0133E, 1996.
We examined the effects of insulin on leg blood flow, whole body
extracellular glucose distribution, and glucose diffusion into the
interstitial fluid (ISF) surrounding skeletal muscle cells in
anesthetized dogs. Extracellular glucose distribution and glucose
diffusion into the muscle ISF were assessed by studying the kinetics
of 14C-L-glucose in plasma and hindlimb lymph. Femoral artery blood
flow was not increased with insulin (7.9+/-0.7 vs. 7.1+/-1.4
ml/min/kg; p=.54). Plasma and lymph dynamics of L-glucose following
intravenous administration were superimposable between saline and
insulin infusion experiments, indicating that insulin did not affect
L-glucose disappearance from plasma or appearance in muscle ISF.
Plasma L-glucose kinetics were best described by a 4-compartment
model, and one of the remote pools (intermediate) predicted the lymph
L-glucose dynamics well. Estimation of maximum glucose diffusion
capacity indicated that this pool, rather than the slowest pool,
represents insulin sensitive tissue. In conclusion, our data indicate
that insulin does not increase transcapillary glucose diffusion to
insulin sensitive cells. In addition, hindlimb lymph represents
primarily skeletal muscle ISF which is represented by an
intermediate, rather than the slowest, remote pool from whole body
compartmental analysis.
Received 9 February 1996; accepted in final form 25 June 1996.
APS Manuscript Number E77-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 25 July 1996