|
 |
|
|||||||
|
|||||||||
© 2001 by the American Diabetes Association, Inc.
The Effect of Insulin on In Vivo Cerebral Glucose Concentrations and Rates of Glucose Transport/Metabolism in Humans
1 Department of Medicine, University of Minnesota Medical School, Minneapolis, Minnesota, and the
2 Department of Radiology, University of Minnesota Medical School, Minneapolis, Minnesota
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 1H-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 µmol/g wet wt when serum insulin = 16 ± 7 pmol/l vs. 5.5 ± 0.3 µmol/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.
CiteULike 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  W. S. Stone and L. J. Seidman Toward a Model of Memory Enhancement in Schizophrenia: Glucose Administration and Hippocampal Function Schizophr Bull, May 15, 2007; (2007) sbm041v1. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Anthony, L. J. Reed, J. T. Dunn, E. Bingham, D. Hopkins, P. K. Marsden, and S. A. Amiel Attenuation of Insulin-Evoked Responses in Brain Networks Controlling Appetite and Reward in Insulin Resistance: The Cerebral Basis for Impaired Control of Food Intake in Metabolic Syndrome? Diabetes, November 1, 2006; 55(11): 2986 - 2992. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. I. Duarte, T. Proenca, C. R. Oliveira, M. S. Santos, and A. C. Rego Insulin restores metabolic function in cultured cortical neurons subjected to oxidative stress. Diabetes, October 1, 2006; 55(10): 2863 - 2870. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. M. Lubow, I. G. Pinon, A. Avogaro, C. Cobelli, D. M. Treeson, K. A. Mandeville, G. Toffolo, and P. J. Boyle Brain oxygen utilization is unchanged by hypoglycemia in normal humans: lactate, alanine, and leucine uptake are not sufficient to offset energy deficit Am J Physiol Endocrinol Metab, January 1, 2006; 290(1): E149 - E153. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. W. Schwartz and D. Porte Jr. Diabetes, Obesity, and the Brain Science, January 21, 2005; 307(5708): 375 - 379. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Huang, R. I. Hollingsworth, R. Castellani, and B. Zipser Accumulation of high-molecular-weight amylose in Alzheimer's disease brains Glycobiology, May 1, 2004; 14(5): 409 - 416. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. M. Bingham, D. Hopkins, D. Smith, A. Pernet, W. Hallett, L. Reed, P. K. Marsden, and S. A. Amiel The Role of Insulin in Human Brain Glucose Metabolism: An 18Fluoro-Deoxyglucose Positron Emission Tomography Study Diabetes, December 1, 2002; 51(12): 3384 - 3390. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Diabetes | Diabetes Care | Clinical Diabetes | Diabetes Spectrum |