The effect of insulin on in vivo cerebral glucose concentrations and rates of glucose transport/metabolism in humans.

Details

Serval ID
serval:BIB_E4CEB13F3C9D
Type
Article: article from journal or magazin.
Collection
Publications
Title
The effect of insulin on in vivo cerebral glucose concentrations and rates of glucose transport/metabolism in humans.
Journal
Diabetes
Author(s)
Seaquist E.R., Damberg G.S., Tkac I., Gruetter R.
ISSN
0012-1797 (Print)
ISSN-L
0012-1797
Publication state
Published
Issued date
2001
Volume
50
Number
10
Pages
2203-2209
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, P.H.S.Publication Status: ppublish
Abstract
The continuous delivery of glucose to the brain is critically important to the maintenance of normal metabolic function. However, elucidation of the hormonal regulation of in vivo cerebral glucose metabolism in humans has been limited by the lack of direct, noninvasive methods with which to measure brain glucose. In this study, we sought to directly examine the effect of insulin on glucose concentrations and rates of glucose transport/metabolism in human brain using (1)H-magnetic resonance spectroscopy at 4 Tesla. Seven subjects participated in paired hyperglycemic (16.3 +/- 0.3 mmol/l) clamp studies performed with and without insulin. Brain glucose remained constant throughout (5.3 +/- 0.3 micromol/g wet wt when serum insulin = 16 +/- 7 pmol/l vs. 5.5 +/- 0.3 micromol/g wet wt when serum insulin = 668 +/- 81 pmol/l, P = NS). Glucose concentrations in gray matter-rich occipital cortex and white matter-rich periventricular tissue were then simultaneously measured in clamps, where plasma glucose ranged from 4.4 to 24.5 mmol/l and insulin was infused at 0.5 mU. kg(-1). min(-1). The relationship between plasma and brain glucose was linear in both regions. Reversible Michaelis-Menten kinetics fit these data best, and no differences were found in the kinetic constants calculated for each region. These data support the hypothesis that the majority of cerebral glucose uptake/metabolism is an insulin-independent process in humans.
Keywords
Adult, Biological Transport, Brain/drug effects, Brain/metabolism, Cerebral Ventricles/metabolism, Female, Glucose/metabolism, Glucose Clamp Technique, Humans, Hypoglycemic Agents/blood, Hypoglycemic Agents/pharmacology, Insulin/blood, Insulin/pharmacology, Kinetics, Magnetic Resonance Spectroscopy, Male, Occipital Lobe/metabolism, Osmolar Concentration, Reference Values
Pubmed
Web of science
Create date
04/08/2010 15:28
Last modification date
20/08/2019 16:08
Usage data