Document Detail


Metabolic sensors mediate hypoglycemic detection at the portal vein.
MedLine Citation:
PMID:  16644683     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The current study sought to ascertain whether portal vein glucose sensing is mediated by a metabolic fuel sensor analogous to other metabolic sensors presumed to mediate hypoglycemic detection (e.g., hypothalamic metabosensors). We examined the impact of selectively elevating portal vein concentrations of lactate, pyruvate, or beta-hydroxybutyrate (BHB) on the sympathoadrenal response to insulin-induced hypoglycemia. Male Wistar rats (n = 36), chronically cannulated in the carotid artery (sampling), jugular vein (infusion), and portal vein (infusion), underwent hyperinsulinemic-hypoglycemic ( approximately 2.5 mmol/l) clamps with either portal or jugular vein infusions of lactate, pyruvate, or BHB. By design, arterial concentrations of glucose and the selected metabolite were matched between portal and jugular (NS). Portal vein concentrations were significantly elevated in portal versus jugular (P < 0.0001) for lactate (5.03 +/- 0.2 vs. 0.84 +/- 0.08 mmol/l), pyruvate (1.81 +/- 0.21 vs. 0.42 +/- 0.03 mmol/l), or BHB (2.02 +/- 0.1 vs. 0.16 +/- 0.03 mmol/l). Elevating portal lactate or pyruvate suppressed both the epinephrine (64% decrease; P < 0.01) and norepinephrine (75% decrease; P < 0.05) responses to hypoglycemia. In contrast, elevating portal BHB levels failed to impact epinephrine (P = 0.51) or norepinephrine (P = 0.47) levels during hypoglycemia. These findings indicate that hypoglycemic detection at the portal vein is mediated by a sensor responding to some metabolic event(s) subsequent to the uptake and oxidation of glucose.
Authors:
Aleksey V Matveyenko; Casey M Donovan
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural    
Journal Detail:
Title:  Diabetes     Volume:  55     ISSN:  0012-1797     ISO Abbreviation:  Diabetes     Publication Date:  2006 May 
Date Detail:
Created Date:  2006-04-28     Completed Date:  2006-06-26     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0372763     Medline TA:  Diabetes     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1276-82     Citation Subset:  AIM; IM    
Affiliation:
Departments of Kinesiology and Integrative Biology, University of Southern California, 3560 Watt Way, PED 107, Los Angeles, CA 90089-0652, USA. donovan@usc.edu
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MeSH Terms
Descriptor/Qualifier:
Animals
Biosensing Techniques / methods*
Blood Glucose / metabolism*
Glucose Clamp Technique
Hypoglycemia / blood*
Kinetics
Lactates / blood
Male
Portal Vein*
Rats
Rats, Wistar
Grant Support
ID/Acronym/Agency:
DK 55257/DK/NIDDK NIH HHS
Chemical
Reg. No./Substance:
0/Blood Glucose; 0/Lactates

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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