Global cerebral blood flow and metabolism during acute hyperketonemia in the awake and anesthetized rat
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Global cerebral blood flow and metabolism during acute hyperketonemia in the awake and anesthetized rat. / Linde, Rasmus; Hasselbalch, Steen G; Topp, Simon; Paulson, Olaf B; Madsen, Peter L.
I: Journal of Cerebral Blood Flow and Metabolism, Bind 26, Nr. 2, 02.2006, s. 170-80.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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TY - JOUR
T1 - Global cerebral blood flow and metabolism during acute hyperketonemia in the awake and anesthetized rat
AU - Linde, Rasmus
AU - Hasselbalch, Steen G
AU - Topp, Simon
AU - Paulson, Olaf B
AU - Madsen, Peter L
PY - 2006/2
Y1 - 2006/2
N2 - In the human setting, it has been shown that acute increase in the concentration of ketone bodies by infusion of beta-hydroxybutyrate increased the cerebral blood flow (CBF) without affecting the overall cerebral metabolic activity. The mechanism by which this effect of ketone bodies was mediated is not known. Alterations in several parameters may possibly explain the increase in CBF and the resetting of the relation between CBF and cerebral metabolism. To study this phenomenon further, we measured global CBF and global cerebral metabolism with the Kety-Schmidt technique in the wakeful rat before and during infusion of ketone bodies. During acute hyperketonemia (average concentration of beta-hydroxybutyrate: 6 mmol/L), global CBF increased 65% from 108 to 178 mL/100 g min and the cerebral metabolic rates for both oxygen and glucose remained constant. This resetting of the relation between CBF and cerebral metabolism could not be explained by alterations in blood pH or arterial CO2 tension. By measuring cerebral intracellular pH by 31P nuclear magnetic resonance spectroscopy, it could further be concluded that the brain pH was unchanged during acute hyperketonemia. These observations indicate that the mechanism responsible for the increase in CBF is rather a direct effect on the cerebral endothelium than via some metabolic interactions.
AB - In the human setting, it has been shown that acute increase in the concentration of ketone bodies by infusion of beta-hydroxybutyrate increased the cerebral blood flow (CBF) without affecting the overall cerebral metabolic activity. The mechanism by which this effect of ketone bodies was mediated is not known. Alterations in several parameters may possibly explain the increase in CBF and the resetting of the relation between CBF and cerebral metabolism. To study this phenomenon further, we measured global CBF and global cerebral metabolism with the Kety-Schmidt technique in the wakeful rat before and during infusion of ketone bodies. During acute hyperketonemia (average concentration of beta-hydroxybutyrate: 6 mmol/L), global CBF increased 65% from 108 to 178 mL/100 g min and the cerebral metabolic rates for both oxygen and glucose remained constant. This resetting of the relation between CBF and cerebral metabolism could not be explained by alterations in blood pH or arterial CO2 tension. By measuring cerebral intracellular pH by 31P nuclear magnetic resonance spectroscopy, it could further be concluded that the brain pH was unchanged during acute hyperketonemia. These observations indicate that the mechanism responsible for the increase in CBF is rather a direct effect on the cerebral endothelium than via some metabolic interactions.
KW - 3-Hydroxybutyric Acid/administration & dosage
KW - Acute Disease
KW - Anesthesia
KW - Animals
KW - Brain/blood supply
KW - Cerebrovascular Circulation/drug effects
KW - Disease Models, Animal
KW - Hydrogen-Ion Concentration
KW - Infusions, Intravenous
KW - Ketone Bodies/blood
KW - Magnetic Resonance Spectroscopy/methods
KW - Male
KW - Phosphorus Isotopes
KW - Rats
KW - Rats, Sprague-Dawley
KW - Sensitivity and Specificity
KW - Sodium Bicarbonate/administration & dosage
KW - Wakefulness/physiology
U2 - 10.1038/sj.jcbfm.9600177
DO - 10.1038/sj.jcbfm.9600177
M3 - Journal article
C2 - 16001018
VL - 26
SP - 170
EP - 180
JO - Journal of Cerebral Blood Flow and Metabolism
JF - Journal of Cerebral Blood Flow and Metabolism
SN - 0271-678X
IS - 2
ER -
ID: 274924507