AJP - Regulatory, Integrative and Comparative Physiology, Vol 243, Issue 1 77-R81, Copyright © 1982 by American Physiological Society
Metabolic and hormonal changes following endotoxin administration to diabetic rats
D. L. Kelleher, B. C. Fong, G. J. Bagby and J. J. Spitzer
The aim of these investigations was to study the time course and cause of
the altered metabolic response of diabetic rats to endotoxin
administration. Escherichia coli endotoxin was administered to
streptozotocin-diabetic and control normoglycemic rats. At 1, 2, 5, 8, and
24 h following endotoxin, animals were decapitated. Plasma samples were
analyzed for glucose, lactate, insulin, glucagon, and corticosteroids. In
addition, tissue glycogen content of liver and skeletal muscle was
determined. Endotoxin caused an elevation of plasma glucose in both
diabetic and normoglycemic rats by 1 h postinjection. The elevation was
prolonged in diabetic rats for 8 h but lasted only 2 h in nondiabetic rats.
Both endotoxin-treated groups demonstrated hyperlactacidemia following
endotoxin. Endotoxin led to liver glycogen depletion in both diabetic and
normoglycemic rats, whereas muscle glycogen content was only slightly
affected. Plasma glucagon and corticosteroids rose immediately and remained
elevated in both endotoxin-treated groups. A significant insulin response
to rising plasma glucose was observed in nondiabetic but not in diabetic
rats following endotoxin. These results suggest that the exaggerated and
prolonged hyperglycemia observed in diabetic endotoxin-treated rats is due
to hypersecretion of glucose-mobilizing hormones and elevated
gluconeogenesis, unmatched by an adequate secretion of insulin to promote
glucose uptake and utilization.
