AJP - Endocrinology and Metabolism, Vol 241, Issue 4 328-E335, Copyright © 1981 by American Physiological Society
Importance of glucagon in mediating epinephrine-induced hyperglycemia in alloxan-diabetic dogs
G. Perez, F. W. Kemmer, H. L. Lickley and M. Vranic
In normal dogs epinephrine stimulates glucose production (Ra) independently
of glucagon. To investigate the role of this interaction in diabetes,
epinephrine (0.1 micrograms . kg-1 . min-1) was infused for 90 min in five
alloxan-diabetic dogs in the presence or absence of somatostatin (0.1
micrograms . kg-1 . min-1). In response to epinephrine, glycemia rose by
40% reflecting a near maximal (122%) increase in Ra. Plasma glucagon (IRG)
rose to 953 pg/ml, whereas insulin (IRI) increased minimally. When
somatostatin was infused with epinephrine to prevent the rise of IRG and
IRI, there was only a marginal increase of glucose concentration (12%) and
production (38%). The effect of somatostatin was reversed by infusing
glucagon (10 ng . kg-1 . min-1) together with epinephrine and somatostatin
into five additional alloxan-diabetic dogs. Increments in IRG, glycemia,
and Ra were fully reestablished. A 100% FFA increase was observed in all
three groups, indicating that the lipolytic effect of epinephrine was
independent of glucagon. In conclusion, in diabetic dogs, in contrast to
normal dogs, epinephrine induced a marked and prolonged increase in glucose
concentration and production mostly through a stimulation of IRG secretion.
