AJP - Regulatory, Integrative and Comparative Physiology, Vol 245, Issue 5 737-R742, Copyright © 1983 by American Physiological Society
Decrease in adenylate cyclase activity in dog livers during endotoxic shock
S. Ghosh and M. S. Liu
The effects of endotoxin administration on adenylate cyclase in dog liver
plasma membranes were studied. The basal, fluoride-, guanine nucleotide-,
isoproterenol-, and glucagon-stimulated adenylate cyclase activities were
decreased by 61, 62, 69, 83, and 63%, respectively, 2 h after in vivo
administration of endotoxin. Endotoxin (100 micrograms/ml) in vitro
decreased the guanine nucleotide-, isoproterenol-, and glucagon-stimulated
adenylate cyclase activities by 24, 25, and 21%, respectively. These data
demonstrate that endotoxin administered in vivo or in vitro had an
inhibitory effect on the adenylate cyclase enzyme system in dog liver
plasma membranes. Because of the involvement of the adenylate
cyclase-adenosine 3',5'-cyclic monophosphate (cAMP) system in the
regulation of hepatic carbohydrate metabolism, the finding that endotoxin
administration decreased adenylate cyclase activity in the liver should
contribute to the understanding of the pathophysiology of altered hepatic
glucose homeostasis during shock.
