Role of epinephrine and norepinephrine in the metabolic response to stress hormone infusion in the conscious dog. Guinness, Owen P. Mc, Vickie Shau, Eric M. Benson, Mike Lewis, Robert T. Snowden, James E. Greene, Doss W. Neal, Alan D. Cherrington. Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville TN 37232-0615
APStracts 4:0132E, 1997.
The role of epinephrine and norepinephrine in contributing to the alterations in hepatic glucose metabolism during a 70 hr stress hormone infusion(SHI) was investigated in 4 groups of chronically catheterized (20 hr fasted) conscious dogs. SHI increased glucagon (5 fold), epinephrine(10 fold), norepinephrine(10 fold) and cortisol(6 fold) levels. Dogs either received all the hormones (SHI; n=5), all the hormones except epinephrine (SHI-EPI;n=6) or all the hormones except norepinephrine (SHI-NE; n=6). In addition six dogs received saline only (SAL). Glucose production (Ra) and gluconeogenesis were assessed after a 70 h hormone or saline infusion, using tracer (33H glucose and U-14C alanine) and arteriovenous difference techniques. SHI increased glucose levels (108+/-2 vs. 189+/-10 mg/dl) and Ra (2.6+/-0.2 vs. 4.1+/-0.3 mg.kg-1min-1) as compared to SAL. The absence of an increase in epinephrine markedly attenuated these changes (glucose and Ra were 140+/-6 mg/dl and 2.7+/-0.4 mg.kg-1.min -1,respectively). Only 25% of the blunted rise in Ra could be accounted for by an attenuation of the rise in net hepatic gluconeogenic precursor uptake (0.9+/-0.1, 1.5+/-0.1 and 1.1+/-0.2 mg.kg-1.min-1; SAL, SHI and SHI-EPI, respectively). The absence of an increase in norepinephrine did not blunt the rise in arterial glucose levels, Ra or net hepatic gluconeogenic precursor uptake (they rose to 195+/-21 mg/dl, 3.7+/-0.5 mg.kg-1.min-1 and 1.7+/-0.2 mg.kg-1.min -1, respectively). In summary, during chronic stress hormone infusion the rise in epinephrine exerts potent stimulatory effects on glucose production principally by enhancing hepatic glycogenolysis, although the rise in circulating norepinephrine has minimal effects. 

Received 21 January 1997; accepted in final form 10 June 1997
APS Manuscript Number E030-7.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 1 July 1997