Diabetes, Vol 44, Issue 6 672-681, Copyright © 1995 by American Diabetes Association
Effects of an acute increase in epinephrine and cortisol on carbohydrate metabolism during insulin deficiency
RE Goldstein, NN Abumrad, DB Lacy, DH Wasserman and AD Cherrington
Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
This study was undertaken to investigate the effects of an acute increase
in the plasma epinephrine level, with or without an accompanying increase
in the plasma cortisol level, during selective insulin deficiency on
glycogenolysis and gluconeogenesis in conscious overnight-fasted dogs.
Experiments consisted of an 80-min tracer and dye equilibration period, a
40-min basal period, and a 180-min experimental period. In all protocols,
selective insulin deficiency was created during the experimental period by
infusing somatostatin peripherally (0.8 micrograms.kg-1.min-1) with basal
replacement of glucagon intraportally (0.65 ng.kg-1.min-1). In EPI+SAL (n =
6), an additional infusion of epinephrine (0.04 micrograms.kg-1.min-1) was
infused during the experimental period along with saline. In EPI+CORT (n =
6), hydrocortisone (3.0 microgram.kg-1.min-1) was infused in addition to
epinephrine during the experimental period. In SAL+CORT (n = 5),
hydrocortisone was infused during the experimental period. In SALINE (n =
5), neither epinephrine nor cortisol was infused. [3-3H]glucose,
[U-14C]alanine, and indocyanine green dye were used to assess glucose
production (rate of appearance [Ra]) and gluconeogenesis using tracer and
arteriovenous difference techniques. During selective insulin deficiency in
SALINE, the arterial plasma glucose level increased from 6.0 +/- 0.1 to
15.8 +/- 1.1 mmol/l; Ra increased from 14.7 +/- 0.7 to 24.9 +/- 1.7
mumol.kg-1.min-1. Gluconeogenic efficiency and the conversion of alanine
and lactate to glucose increased to 300 +/- 55 and 355 +/- 67% of basal. In
EPI+SAL and EPI+CORT, plasma glucose increased from 6.2 +/- 0.1 to 19.8 +/-
0.9 mmol/l and from 6.3 +/- 0.1 to 19.5 +/- 0.9 mmol/l. In EPI+SAL and
EPI+CORT, Ra increased from 16.5 +/- 1.1 to 29.3 +/- 3.2 mumol.kg-1.min-1
and from 15.4 +/- 1.3 to 28.3 +/- 2.5 mumol.kg-1.min-1. The rise in
gluconeogenic efficiency was similar to the rise that occurred in SALINE,
but gluconeogenic conversion increased 17-fold in each of the two
epinephrine groups. During the epinephrine infusion, gluconeogenesis
accounted for a maximum of 55% of total glucose production as opposed to
31% during insulin deficiency alone. An increase in cortisol alone during
insulin deficiency (SAL+CORT) had no effect on glucose level, glucose
production, or gluconeogenesis. These results suggest that small increases
in the plasma epinephrine level during insulin deficiency can significantly
worsen the resulting hyperglycemia through stimulation of both
glycogenolysis and gluconeogenesis.(ABSTRACT TRUNCATED AT 400 WORDS)