UNIGE document Scientific Article
previous document  unige:32959  next document
add to browser collection

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

Published in Journal of neurochemistry. 2009, vol. 109 Suppl 1, p. 38-45
Abstract 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.
Keywords AlgorithmsAnimalsBiological Transport, Active/physiologyBlood Glucose/metabolismBlood-Brain Barrier/physiologyBrain/anatomy & histologyBrain Chemistry/physiologyGlucose/metabolismGlucose Transporter Type 1/metabolismGlycogen/metabolismHypothalamus/metabolismKineticsLiver Glycogen/metabolismMaleMicrowavesRatsRats, Sprague-DawleyReproducibility of ResultsTissue Fixation
PMID: 19393007
Full text
Article (Published version) (216 Kb) - public document Free access
Research group CIBM (863)
(ISO format)
POITRY-YAMATE, Carole, LEI, Hongxia, GRUETTER, Rolf. The rate-limiting step for glucose transport into the hypothalamus is across the blood-hypothalamus interface. In: Journal of Neurochemistry, 2009, vol. 109 Suppl 1, p. 38-45. doi: 10.1111/j.1471-4159.2009.05934.x https://archive-ouverte.unige.ch/unige:32959

459 hits



Deposited on : 2014-01-08

Export document
Format :
Citation style :