AJP - Regulatory, Integrative and Comparative Physiology, Vol 264, Issue 2 254-R261, Copyright © 1993 by American Physiological Society
Role of somatostatin in glucose regulation during endotoxicosis in the rat
M. R. Yelich, D. M. Umporowicz and B. A. Drolet
Department of Physiology, Stritch School of Medicine, Maywood, Illinois.
This study assessed the role of somatostatin in regulating glucose
homeostasis during endotoxicosis in the rat. Plasma levels of somatostatin,
glucose, lactate, insulin, and glucagon were measured in control and
endotoxin-treated rats. Cysteamine was used to block endogenous
somatostatin release before endotoxin treatment. Early during the course of
endotoxicosis, plasma levels of somatostatin-like immunoreactivity (SLI)
were significantly elevated along with glucose, lactate, insulin, and
glucagon. Pretreatment of endotoxic rats with cysteamine virtually blocked
the elevated SLI levels and prevented the early appearance of
hyperglycemia. Endotoxin-induced increases in lactic acid and glucagon
levels were attenuated by cysteamine pretreatment, but elevated insulin
levels were not appreciably altered. Elevated somatostatin levels appeared
to support the occurrence of the early hyperglycemia and prevent the
development of late hypoglycemia during endotoxicosis by sustaining
elevated glucagon levels and thus facilitating the maintenance of glucose
levels. The results suggest that somatostatin plays a significant role in
the glucoregulatory response to endotoxicosis. Endotoxicosis may alter the
relative "physiological" ability of somatostatin to inhibit the secretion
of insulin and glucagon.
