AJP - Endocrinology and Metabolism, Vol 269, Issue 5 E927-E933, Copyright © 1995 by American Physiological Society
Glucocorticoid deprivation alters in vivo glucose uptake by muscle and adipose tissues of GTG-obese mice
S. C. Blair, I. D. Caterson and G. J. Cooney
Department of Endocrinology, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia.
The effect of 1 wk of glucocorticoid deprivation by surgical adrenalectomy
(ADX) on tissue 2-deoxy(-)[U-14C]glucose (2-DG) uptake and hepatic glucose
production (HGP) was assessed in conscious, catheterized mice 5 wk after
the induction of obesity with gold thioglucose (GTG). Despite the
prevailing hyperglycemia and hyperinsulinemia, glucose uptake by heart,
quadriceps muscle, and interscapular brown adipose tissue (BAT) of
GTG-obese mice was unchanged compared with controls, suggesting that the
hyperglycemia of GTG-obese mice is able to compensate for the insulin
resistance of these tissues. In contrast, epididymal white adipose tissue
(WAT) of GTG-obese mice showed increased glucose uptake with hyperglycemia
and hyperinsulinemia. ADX decreased the hyperglycemia and lowered the
elevated glycogen content of the liver of GTG-obese mice. ADX reduced
glucose uptake by heart and WAT of control and GTG-obese mice, consistent
with the concomitant decrease in insulinemia. Glucose uptake by muscle of
control and GTG-obese mice was not significantly decreased after ADX
despite the decrease in insulin, and ADX increased glucose uptake by BAT of
GTG-obese mice, suggesting increased sympathetically mediated thermogenesis
in this tissue. HGP was increased in GTG-obese mice compared with controls,
and ADX significantly reduced HGP in both GTG-obese and control mice. These
results suggest that the improved glucose tolerance of ADX GTG-obese mice
and ADX control mice is due to a decrease in HGP rather than an increase in
peripheral glucose uptake.
