AJP - Endocrinology and Metabolism, Vol 240, Issue 2 175-E183, Copyright © 1981 by American Physiological Society
Effects of dietary composition on glucose metabolism in rat adipose cells
L. B. Salans, J. E. Foley, L. J. Wardzala and S. W. Cushman
The effect of altered dietary carbohydrate and fat content on equilibrium
insulin binding to, and glucose transport activity and metabolism in,
isolated rat epididymal adipose cells has been studied. Alterations in
basal and insulin-stimulated total glucose utilization induced by changes
in the ratio of dietary carbohydrate to fat are accounted for by specific
effects of dietary composition at two levels of cellular function: 1)
glucose transport across the cell's plasma membrane, specifically, the
number of functional glucose transport systems, and 2) the cell's maximal
capacity for glucose metabolism. These effects occur without alterations in
insulin binding or the cell's sensitivity to insulin. Furthermore,
diet-induced changes in the pattern of 14CO2, and 14C-triglyceride glycerol
and fatty acid production appear to be accounted for primarily by the
influence of dietary composition on the total amount of glucose entering
the cell. Thus, under the conditions of this study, changes in dietary
composition alter the adipose cell's capacities for glucose transport and
metabolism without altering the mechanisms of insulin action or regulating
the metabolic flow of glucose carbons.
