Contributions of liver and kidneys to glycerol production and
utilization in the dog.
Previs, Stephen F., Spencer K. Martin, Jeffrey W. Hazey, Maxim V.
Soloviev, Adam P. Keating, David Lucas, France David, John Koshy,
Donn W. Kirschenbaum, Kou-Yi Tserng, and Henri Brunengraber.
Departments of Nutrition and Surgery, Case Western Reserve
University, Cleveland, Ohio 44106 and Department of Radiology, Mt.
Sinai Medical Center, Cleveland OH 44106
APStracts 3:0166E, 1996.
The classical concept holds that liver and kidneys are the main sinks
of glycerol released by adipose tissue. However, rates of glycerol
appearance exceed the rate of glycerol delivery to liver and kidneys.
We measured the hepatic and renal contributions to glycerol
production and utilization in anesthetized dogs that were either
overnight-fasted or 24h-fasted after three days on a carbohydrate
-free diet. Dogs were infused with [2H5]glycerol, and the
concentration and 2H-enrichment of glycerol were measured across
liver and kidney. After a baseline period, either norepinephrine or
glucose plus insulin was infused to alter the rate of glycerol
production. Our study shows that the production of glycerol by liver
and kidneys amounted to 4 to 9% and 4 to 7% of the Ra of glycerol,
respectively. Uptake of glycerol by liver and kidneys amounted to 26
to 30% and 10 to 19% of the rate of appearance of glycerol,
respectively. Thus, contrary to the classical concept, the bulk of
glycerol utilization occurs in non-hepatic, non-renal tissues that
have very low glycerol kinase activity per gram.
Received 9 May 1996; accepted in final form 30 July 1996.
APS Manuscript Number E231-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 29 August 1996