The rate-limiting step for glucose transport into the hypothalamus is across the blood-hypothalamus interface.

Détails

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Etat: Serval
Version: de l'auteur
ID Serval
serval:BIB_7BD16F6EF4A6
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
The rate-limiting step for glucose transport into the hypothalamus is across the blood-hypothalamus interface.
Périodique
Journal of Neurochemistry
Auteur(s)
Poitry-Yamate C., Lei H., Gruetter R.
ISSN
1471-4159 (Electronic)
ISSN-L
0022-3042
Statut éditorial
Publié
Date de publication
2009
Peer-reviewed
Oui
Volume
109
Numéro
Suppl. 1
Pages
38-45
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't Publication Status: ppublish
Résumé
Specialized glucosensing neurons are present in the hypothalamus, some of which neighbor the median eminence, where the blood-brain barrier has been reported leaky. A leaky blood-brain barrier implies high tissue glucose levels and obviates a role for endothelial glucose transporters in the control of hypothalamic glucose concentration, important in understanding the mechanisms of glucose sensing We therefore addressed the question of blood-brain barrier integrity at the hypothalamus for glucose transport by examining the brain tissue-to-plasma glucose ratio in the hypothalamus relative to other brain regions. We also examined glycogenolysis in hypothalamus because its occurrence is unlikely in the potential absence of a hypothalamus-blood interface. Across all regions the concentration of glucose was comparable at a given plasma glucose concentration and was a near linear function of plasma glucose. At steady-state, hypothalamic glucose concentration was similar to the extracellular hypothalamic glucose concentration reported by others. Hypothalamic glycogen fell at a rate of approximately 1.5 micromol/g/h and remained present in substantial amounts. We conclude for the hypothalamus, a putative primary site of brain glucose sensing that: the rate-limiting step for glucose transport into brain cells is at the blood-hypothalamus interface, and that glycogenolysis is consistent with a substantial blood -to- intracellular glucose concentration gradient.
Mots-clé
Algorithms, Animals, Biological Transport, Active/physiology, Blood Glucose/metabolism, Blood-Brain Barrier/physiology, Brain/anatomy & histology, Brain Chemistry/physiology, Glucose/metabolism, Glucose Transporter Type 1/metabolism, Glycogen/metabolism, Hypothalamus/metabolism, Kinetics, Liver Glycogen/metabolism, Male, Microwaves, Rats, Rats, Sprague-Dawley, Reproducibility of Results, Tissue Fixation
Pubmed
Web of science
Création de la notice
04/08/2010 16:28
Dernière modification de la notice
03/03/2018 18:36
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