Neural and pancreatic influences on net hepatic glucose uptake and
glycogen synthesis.
Moore, Mary Courtney, Luciano Rossetti, Michael J. Pagliassotti,
Michael Monahan, Carol Venable, Doss Neal, and Alan D. Cherrington.
Department of Molecular Physiology and Biophysics, Vanderbilt
University, Nashville, TN 37232 and Division of Endocrinology,
Department of Medicine, Albert Einstein College of Medicine, New
York, NY 10461
APStracts 3:0061E, 1996.
The role of the liver nerves in the disposition of peripherally
administered glucose was examined in 7 hepatic-innervated (HI) and 9
hepatic-denervated (HD) 42-h-fasted conscious dogs. After a 40-min
basal period, there was a 4-h experimental period during which the
hepatic glucose load was increased 2-fold via peripheral glucose
infusion. Somatostatin was infused to suppress pancreatic endocrine
secretion, and insulin and glucagon were infused intraportally to
produce a 4-fold increase in insulin and a gradual decrease (25%) in
glucagon. The area under the curve of net hepatic glucose uptake
(NHGU) during the glucose infusion period totaled 483+/-82 mg/kg and
335+/-32 mg/kg in HD and HI, respectively (p<0.05). The area
under the curve of the hepatic fractional extraction of glucose was
27% greater in HD (p<0.05). Net hepatic lactate output was
similar in the two groups, and net hepatic glycogen synthesis was
3.8+/-0.8 v 2.7+/-0.5 mg.kg dog wt-1.min-1 in HD and HI, respectively
(p=0.13). The direct pathway of glycogen synthesis was responsible
for 54-58% of net hepatic glycogen synthesis in both HI and HD (n=6
for both). In summary: 1) NHGU in response to peripheral glucose
infusion was 44% greater in HD than in HI, 2) net hepatic glycogen
synthesis was enhanced by 41% in HD although the probability of this
change was 0.13, and 3) the contribution of the direct pathway to
glycogen synthesis was the same in HD and HI. These data are
consistent with a role for the liver nerves in regulating the
magnitude of NHGU in response to glucose administration. They also
indicate that the absence of liver nerves may reduce glycogen
turnover during glucose infusion.
Received 22 June 1995; accepted in final form 5 March 1996.
APS Manuscript Number E287-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 20 March 96