AJP - Endocrinology and Metabolism, Vol 254, Issue 3 E342-E348, Copyright © 1988 by American Physiological Society
Increased in vivo glucose utilization in 30-day-old obese Zucker rat: role of white adipose tissue
S. Krief, R. Bazin, F. Dupuy and M. Lavau
Institut National de la Sante et de la Recherche Medicale U177, Paris, France.
In vivo whole-body glucose utilization and uptake in multiple individual
tissues were investigated in conscious 30-day-old Zucker rats, which when
obese are hyperphagic, hyperinsulinemic, and normoglycemic. Whole-body
glucose metabolism (assessed by [3-3H]glucose) was 40% higher in obese
(fa/fa) than in lean (Fa/fa) rats, suggesting that obese rats were quite
responsive to their hyperinsulinemia (140 vs. 55 microU/ml). In obese
compared with lean rats, tissue glucose uptake (assessed by the
2-deoxyglucose technique) was increased by 15, 12, and 6 times in dorsal,
inguinal, perigonadal white depots, respectively; multiplied by 2.5 in
brown adipose tissue; increased by 50% in skin from inguinal region but not
in that from cranial, thoracic, or dorsal area; and increased twofold in
diaphragm but similar in heart, in proximal intestine, and in total
muscular mass of limbs. Our data establish that in young obese rats the
hypertrophied white adipose tissue was a major glucose-utilizing tissue
whose capacity for glucose disposal compared with that of half the muscular
mass. Adipose tissue could therefore play an important role in the
homeostasis of glucose in obese rats in the face of their increased
carbohydrate intake.
