Determination of Isotopic Label in Acetaminophen Glucuronide, a Noninvasive Probe of Intrahepatic Glucose Metabolism
Loading...
Authors
Bachman, Mark W.
Issue Date
1995
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
When used in conjunction with isotopic tracers, acetaminophen glucuronide
(AG) can serve as a probe of hepatic glucose and glycogen metabolism because the
glucuronidation of acetaminophen involves uridine diphosphate-glucuronic acid
(UDP-glucuronic which is derived from UDP-glucose, the immediate precursor
of glycogen. The in vivo studies in humans and other animals involve the infusion of stable and/or radioactive tracers such as glucose, galactose, and gluconeogenic
precursors which are metabolized in the liver to UDP-glucose. Administration of
acetaminophen, with subsequent collection of AG in the urine and analysis of the
amount of tracer converted to the glucuronide, allows one to trace metabolic pathways
of hepatic glycogen synthesis. Most previous methods using this glycoconjugate
require the cumbersome conversion of glucuronide from urinary AG to glucose in
order to obtain quantitative results. The novel methods described in this report allow
the direct determination of label in AG, without the time-consuming conversion of
glucuronide into glucose. AG can be isolated from the urine, purified by ion
exchange chromatography, and the amount of its label, either stable or radioactive,
can be rapidly determined. For stable tracers, the column eluate is dried and
derivatized to make it more volatile and prepare it for percent enrichment analysis
with gas chromatography/mass spectroscopy (GC/MS). For radioactive label, the
procedure involves further purification of the column eluate by high-performance
liquid chromatography (HPLC), collection of the AG peak from the HPLC, and
determination of the radioactivity by liquid scintillation spectroscopy.
With honors.
With honors.
Description
viii, 96 p.
Citation
Publisher
Kalamazoo College
License
U.S. copyright laws protect this material. Commercial use or distribution of this material is not permitted without prior written permission of the copyright holder.