ISSN:
1432-1912
Keywords:
Isolated Perfused Rat Brain
;
High-Energy Phosphates
;
Glycolytic Pathway
;
Thiopental
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The effects of glucose concentrations in the perfusion medium ranging from 5 to 15 mM and thiopental, on cerebral energy metabolism were studied using the isolated perfused rat brain. After a perfusion time of 30 min brain levels of the following substrates and metabolites were determined: P-creatine, ATP, ADP, AMP, glycogen, glucose, glucose-6-P, fructose-6-P, pyruvate, lactate, α-ketoglytarate, glutamate, ammonia. In control experiments increasing the glucose concentration in the perfusion medium produced an increase of intracellular brain glucose concentration only, revealing a linear relationship between glucose content in brain and blood. Neither high-energy phosphates nor glycolytic intermediates were markedly affected by the changes in blood glucose. With an anesthetic dose of thiopental (0.15 mM) in the perfusion medium identical metabolic alterations occurred in all experiments: P-creatine and glucose were significantly increased whereas ADP, AMP, lactate and pyruvate were diminished. Also with thiopental brain glucose was linearly related with the glucose concentration in the perfusion medium. The calculated regression line was apparently parallel with that from control experiments; that means thiopental always caused an elevation of brain glucose by the same amount of 0.9 μmoles/g—irrespective of the initial cerebral glucose content. The results yield further evidence that glucose transport is not the rate-limiting step in glycolysis. The action of thiopental on glycolytic pathway is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00508413
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