Kinetics of glucose delivery to subcutaneous tissue in rats
measured with 0.3 mm amperometric microsensors.
Quinn, C. P., M. V. Pishko, D. W. Schmidtke, M. Ishikawa, J. G.
Wagner, P. Raskin, J. A. Hubbell, and A. Heller.
Department of Chemical Engineering, The University of Texas at
Austin, Austin, Texas, 78712-1062, USA, Department of Internal
Medicine, The University of Texas, Southwestern Medical School,
Dallas, Texas, 75235-8858, USA
APStracts 2:0041E, 1995.
The time between intravenous injection of a glucose bolus and the time
the glucose concentration peaked in the subcutaneous tissue was
measured in pentobarbital anesthetized rats with implanted 290 [mu]m
diameter amperometric sensors. Boluses of 100, 200 and 400 mg/kg body
weight were injected. The glucose concentration in the jugular vein
was monitored by frequent withdrawal and analysis of samples. The
glucose concentration in the subcutaneous tissue was continuously
monitored with the sensors. The times required for the subcutaneously
implanted sensor to reach its maxima, corrected for sensor response
time, were 7.5 + 3.9 min, 9.8 + 5.5 min and 10.0 + 4.4 min for the
smallest to the largest dose, respectively. The shorter delay in
response to the smallest dose was statistically significant (p <
0.03). The results were consistent with dilution of the bolus in the
cardiovascular system and transport of glucose both by diffusion and
by facilitated transport via a saturable mediator. An understanding
of the differences in the dynamics of venous versus subcutaneous
response to a glucose dose is important in developing algorithms for
the control of blood glucose based on a subcutaneous measurement.
Received 28 November 1994; accepted in final form 21 February
1995.
APS Manuscript Number E489-4.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 10 March 1995.