Journal of Applied Physiology, Vol 40, Issue 6 855-863, Copyright © 1976 by American Physiological Society

ARTICLES

Glucagon and plasma catecholamines during beta-receptor blockade in exercising man

H. Galbo, J. J. Holst, N. J. Christensen and J. Hilsted

Seven men ran at 60% of individual maximal oxygen uptake to exhaustion during beta-adrenergic blockade with propranolol (P), during lipolytic blockade with nicotinic acid (N), or without drugs (C). The total work times (83 +/- 9 (P), 122 +/- 8 (N), 166 +/- 10 (C) min, mean and SE) differed significantly. Epinephrine rose progressively above preexercise levels (0.06 +/- 0.01 ng/ml); at exhaustion concentrations in P experiments (2.15 +/- 0.41) were larger than in N (1.08 +/- 0.31) and C (0.72 +/- 0.28) experiments. Norepinephrine increased consistently while insulin decreased. After an initial decrease glucagon concentrations increased progressively in parallel with declining plasma glucose and were at exhaustion always three times preexercise values. Thus beta-adrenergic blockade did not diminish the glucagon response. Nor was this response increased when alpha-receptor stimulation in P experiments was intensified. Carbohydrate combustion was smaller and NEFA and glycerol concentrations in serum larger during C experiments. Alanine concentrations were never raised at exhaustion. Accordingly, neither stimulation of adrenergic receptors nor NEFA and alanine concentrations are major determinants for the exercise-induced glucagon secretion in man. It is suggested that decreased glucose availability enhances the secretion of glucagon and epinephrine during prolonged exercise.

This article has been cited by other articles:

				E. M. Snyder, S. T. Turner, and B. D. Johnson {beta}2-Adrenergic Receptor Genotype and Pulmonary Function in Patients With Heart Failure. Chest, November 1, 2006; 130(5): 1527 - 1534. [Abstract] [Full Text] [PDF]

				J. K. Apple, E. B. Kegley, D. L. Galloway, T. J. Wistuba, L. K. Rakes, and J. W. S. Yancey Treadmill exercise is not an effective methodology for producing the dark-cutting condition in young cattle J Anim Sci, November 1, 2006; 84(11): 3079 - 3088. [Abstract] [Full Text] [PDF]

				O. Hansson, M. Donsmark, C. Ling, P. Nevsten, M. Danfelter, J. L. Andersen, H. Galbo, and C. Holm Transcriptome and proteome analysis of soleus muscle of hormone-sensitive lipase-null mice J. Lipid Res., December 1, 2005; 46(12): 2614 - 2623. [Abstract] [Full Text] [PDF]

				A. K. Hansen, T. Clausen, and O. B. Nielsen Effects of lactic acid and catecholamines on contractility in fast-twitch muscles exposed to hyperkalemia Am J Physiol Cell Physiol, July 1, 2005; 289(1): C104 - C112. [Abstract] [Full Text] [PDF]

				D. G. Hunt and J. L. Ivy Epinephrine inhibits insulin-stimulated muscle glucose transport J Appl Physiol, November 1, 2002; 93(5): 1638 - 1643. [Abstract] [Full Text] [PDF]

				D. G. Hunt, Z. Ding, and J. L. Ivy Propranolol prevents epinephrine from limiting insulin-stimulated muscle glucose uptake during contraction J Appl Physiol, August 1, 2002; 93(2): 697 - 704. [Abstract] [Full Text] [PDF]

				J. J. Hamann, K. M. Kelley, and L. B. Gladden Effect of epinephrine on net lactate uptake by contracting skeletal muscle J Appl Physiol, December 1, 2001; 91(6): 2635 - 2641. [Abstract] [Full Text] [PDF]

				R. J. Geor, K. W. Hinchcliff, and R. A. Sams beta -Adrenergic blockade augments glucose utilization in horses during graded exercise J Appl Physiol, September 1, 2000; 89(3): 1086 - 1098. [Abstract] [Full Text] [PDF]

				D. K. Rohrer, A. Chruscinski, E. H. Schauble, D. Bernstein, and B. K. Kobilka Cardiovascular and Metabolic Alterations in Mice Lacking Both beta 1- and beta 2-Adrenergic Receptors J. Biol. Chem., June 11, 1999; 274(24): 16701 - 16708. [Abstract] [Full Text] [PDF]