AJP - Endocrinology and Metabolism, Vol 265, Issue 5 E743-E751, Copyright © 1993 by American Physiological Society
Liver and peripheral tissue glycogen metabolism in obese mice: effect of a mixed meal
C. Chen, P. F. Williams and I. D. Caterson
Department of Endocrinology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia.
Glycogen metabolism in the liver, skeletal muscle, cardiac muscle, and
white adipose tissue was studied in gold thioglucose (GTG) obese mice after
fasting and during refeeding. Prolonged (48 h) fasted control and GTG mice
were refed with standard laboratory diet for 24 h. During fasting and
refeeding, the changes in glycogen content and the activity of glycogen
synthase I and R and phosphorylase alpha in the liver were similar in lean
and GTG mice. However, the glycogen storage in the livers from GTG mice was
always greater than that in lean animals. In GTG mice the activity of liver
glycogen synthase I and R was significantly higher than that in lean
animals 3 and 6 h after refeeding. The activity of liver phosphorylase
alpha in GTG mice was higher than that in lean mice after refeeding. There
were no significant differences in the glycogen content of white adipose
tissue, cardiac muscle, and skeletal muscle from lean and GTG mice during
the entire study. The results of this study suggest that increased glycogen
storage in the liver is a major alteration in nonoxidative glucose
metabolism and contributes to the development of insulin resistance and
glucose intolerance in GTG obese mice.
