The role of glucagon in the maintenance of euglycemia in fed and
fasted rats.
Brand, Christian Lehn, Peer Norbert Jorgensen, Ulrik Knigge, Jorgen
Warberg, Ivan Svendsen, Jorgen Smedegaard Kristensen, Jens Juul
Holst.
Diabetes Pharmacology, Immunochemical Dept., Hybridoma Lab, Medical
Affairs, Novo Nordisk, DK-2880 Bagsvard, Denmark; Dept. of Medical
Physiology, Panum Institute, University of Copenhagen, DK-2200
Copenhagen N, Denmark
APStracts 2:0090E, 1995.
The role of glucagon in the regulation of blood glucose in fed and
fasted, anaesthetized rats was studied by injecting intravenously 4
ml/kg of a high-capacity (40 nmol/ml), high-affinity (0.6 x 1011
L/mol) monoclonal glucagon antibody. Blood glucose was lowered by the
antibody by 2 mmol/L in fed rats but remained unchanged in 10 and 48
-h fasted rats. Antibody injection significantly reduced plasma
insulin in both fed and 10-h fasted rats. In 10-h fasted rats
propranolol injection decreased blood glucose by 0.6 mmol/L and
combined with antibody administration a decrease by 1.1 mmol/L was
observed. Blood glucose was never below 3.3 mmol/L. Thus, glucagon is
partly responsible for maintenance of euglycemia in fed rats, whereas
during fasting it plays a limited role. However, immunoneutralization
of glucagon reduces insulin secretion irrespective of blood glucose.
Additional mechanisms seem to be responsible for the maintenance of
blood glucose in the fasting state when glucagon and the sympatho
-adrenergic system are blocked.
Received 2 June 1994; accepted in final form 19 April 1995.
APS Manuscript Number E205-4.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 2 May 1995.