title: Contributions of liver and kidneys to glycerol production and utilization in the dog.
abstract: The classical concept holds that liver and kidneys are the main sinks of glycerol released by adipose tissue. However, rates of glycerol appearance (Ra) 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 fasted either overnight or for 24 h after 3 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 4-9% and 4-7% of the Ra of glycerol, respectively. Uptake of glycerol by liver and kidneys amounted to 26-30 and 10-19% of the Ra of glycerol, respectively. Thus, contrary to the classical concept, the bulk of glycerol utilization occurs in nonhepatic, nonrenal tissues that have very low glycerol kinase activity per gram.
authors.affiliation: Department of Nutrition, Case Western Reserve University, Cleveland Ohio, USA.
authors.forename: S F
authors.initials: SF
authors.lastname: Previs
authors.forename: S K
authors.initials: SK
authors.lastname: Martin
authors.forename: J W
authors.initials: JW
authors.lastname: Hazey
authors.forename: M V
authors.initials: MV
authors.lastname: Soloviev
authors.forename: A P
authors.initials: AP
authors.lastname: Keating
authors.forename: D
authors.initials: D
authors.lastname: Lucas
authors.forename: F
authors.initials: F
authors.lastname: David
authors.forename: J
authors.initials: J
authors.lastname: Koshy
authors.forename: D W
authors.initials: DW
authors.lastname: Kirschenbaum
authors.forename: K Y
authors.initials: KY
authors.lastname: Tserng
authors.forename: H
authors.initials: H
authors.lastname: Brunengraber
mesh_terms: D000818:Animals; D004285:Dogs; D005260:Female; D005990:Glycerol / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008297:Male; D009928:Organ Specificity
chemical_list: D005990:Glycerol