AJP - Endocrinology and Metabolism, Vol 240, Issue 2 112-E118, Copyright © 1981 by American Physiological Society
Hyperinsulinemia and hyperglucagonemia in fasted rats during liver regeneration
R. P. Cornell
The two pancreatic hormones, insulin and glucagon, have been implicated as
hepatotrophic factors for the regenerating liver after partial hepatectomy.
Similar to previous studies, hyperglucagonemia and hypoinsulinemia were
noted following major liver resection of initially well-fed rats. In
contrast to well-fed animals, rats fasted for 24 h prior to surgery to
deplete hepatic glycogen and establish low basal insulin levels developed
both portal venous hyperglucagonemia and hyperinsulinemia after 67%
hepatectomy. Elevation of basal portal venous levels of the two hormones
suggested enhanced pancreatic secretion of insulin and glucagon in response
to acute liver injury in fasted animals. Because polypeptide hormones must
bind to specific hepatic cell membrane receptors to exert their
hepatotrophic influences, basal portal-systemic venous differences of
insulin and glucagon and glucose-elicited portal-hepatic venous insulin
differences were evaluated. The evidence implies that hepatic extraction
and, therefore, cell membrane receptor binding of both insulin and glucagon
by regenerating livers were enhanced even though portal venous levels of
the two hormones were elevated.
