AJP - Endocrinology and Metabolism, Vol 240, Issue 2 83-E87, Copyright © 1981 by American Physiological Society
Hepatic carbohydrate metabolism in the spontaneously diabetic Bio-Breeding Worcester rat
M. C. Appel, A. A. Like, A. A. Rossini, D. B. Carp and T. B. Miller Jr
The effects of diabetes on hepatic carbohydrate metabolism were
investigated in spontaneously diabetic Bio-Breeding Worcester (BB/W) rats.
The juvenile-onset-type syndrome displayed by these animals is
characterized by beta-cell destruction with subsequent ketosis-prone
insulinopenia. Livers from diabetic animals demonstrated increased
adenosine 3',5'-cyclic monophosphate levels but subnormal total protein and
glycogen content. Isolated perfused livers of diabetic BB/W rats
demonstrated an increased rate of glucose production from [14C]lactate and
an impaired rate of glycogen synthesis. These data were consonant with
hepatic enzyme studies demonstrating markedly increased activities of
component gluconeogenic (glucose-6-phosphatase, fructose-1,6-diphosphatase,
phosphoenolpyruvate carboxykinase) and glycogenolytic (glycogen
phosphorylase) enzymes with decreased activities of glycolytic (hexokinase,
pyruvate kinase) and glycogenic (glycogen synthase) enzymes. These findings
agree with previous studies using alloxan- and streptozotocin-induced
diabetic animals and suggest that accelerated hepatic gluconeogenesis and
impaired glucose utilization are pathognomonic of all insulin-deficient
diabetic syndromes.
