|
|
||||||||
1 Department of Animal Sciences, 2 Division of Nutritional Sciences, and 3 Program in Neuroscience, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
Noradrenergic mechanisms in
the hypothalamus may be involved in counterregulatory responses to
glucoprivic episodes. After 2-deoxy-D-glucose (2-DG; 1.2 mmol/kg iv), extracellular norepinephrine (NE) concentration in the
ventromedial hypothalamus (VMN) increased in a bimodal fashion to
251 ± 39% (P < 0.001) and 150 ± 17%
(P < 0.001) of baseline during the first 30 min. In
the lateral hypothalamus (LHA), NE decreased by 30 min (61 ± 4%, P < 0.001) and no consistent changes were
measured in the paraventricular nucleus (PVN). Because the NE response
in the VMN after 2-DG followed the same pattern as GABA, the
interaction between NE and GABA was evaluated. In the VMN, GABA had
little effect on extracellular NE concentrations but NE increased GABA
concentrations 166 ± 13%, (P < 0.01). In the
presence of yohimbine (
2-adrenoceptor antagonist) the
first GABA peak after 2-DG was absent, and the second GABA peak was absent in the presence of timolol (
-adrenoceptor antagonist). These
results support an interaction among noradrenergic and GABAergic systems in the VMN during glucoprivation and that increased NE mediates
the increase in extracellular GABA after 2-DG.
microdialysis; 2-deoxy-D-glucose; timolol; yohimbine
This article has been cited by other articles:
![]() |
B. E. Levin, T. C. Becker, J.-i. Eiki, B. B. Zhang, and A. A. Dunn-Meynell Ventromedial Hypothalamic Glucokinase Is an Important Mediator of the Counterregulatory Response to Insulin-Induced Hypoglycemia Diabetes, May 1, 2008; 57(5): 1371 - 1379. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. Chan, H. Cheng, R. Herzog, D. Czyzyk, W. Zhu, A. Wang, R. J. McCrimmon, M. R. Seashore, and R. S. Sherwin Increased GABAergic Tone in the Ventromedial Hypothalamus Contributes to Suppression of Counterregulatory Reponses After Antecedent Hypoglycemia Diabetes, May 1, 2008; 57(5): 1363 - 1370. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. Chan, M. Lawson, W. Zhu, J. L. Beverly, and R. S. Sherwin ATP-Sensitive K+ Channels Regulate the Release of GABA in the Ventromedial Hypothalamus During Hypoglycemia Diabetes, April 1, 2007; 56(4): 1120 - 1126. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. Chan, W. Zhu, Y. Ding, R. J. McCrimmon, and R. S. Sherwin Blockade of GABAA Receptors in the Ventromedial Hypothalamus Further Stimulates Glucagon and Sympathoadrenal but Not the Hypothalamo-Pituitary-Adrenal Response to Hypoglycemia. Diabetes, April 1, 2006; 55(4): 1080 - 1087. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. G. de Vries, M. A. Lawson, and J. L. Beverly Hypoglycemia-induced noradrenergic activation in the VMH is a result of decreased ambient glucose Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2005; 289(4): R977 - R981. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. G. de Vries, M. A. Lawson, and J. Lee Beverly Dissociation of hypothalamic noradrenergic activity and sympathoadrenal responses to recurrent hypoglycemia Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2004; 286(5): R910 - R915. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. B. Evans, C. W. Wilkinson, K. Bentson, P. Gronbeck, A. Zavosh, and D. P. Figlewicz PVN activation is suppressed by repeated hypoglycemia but not antecedent corticosterone in the rat Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2001; 281(5): R1426 - R1436. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. L. Beverly, M. G. De Vries, S. D. Bouman, and L. M. Arseneau Noradrenergic and GABAergic systems in the medial hypothalamus are activated during hypoglycemia Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2001; 280(2): R563 - R569. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |