scholarly journals Adenosine Mediates Decreased Cerebral Metabolic Rate and Increased Cerebral Blood Flow During Acute Moderate Hypoxia in the Near‐Term Fetal Sheep

2003 ◽  
Vol 553 (3) ◽  
pp. 935-945 ◽  
Author(s):  
Arlin B. Blood ◽  
Christian J. Hunter ◽  
Gordon G. Power
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Metabolic Rate ◽  
Fetal Sheep ◽  
Moderate Hypoxia ◽  
Cerebral Metabolic Rate ◽  
Near Term

Vasopressin and prostanoid mechanisms in control of cerebral blood flow in hypotensive newborn pigs

1990 ◽  
Vol 258 (2) ◽  
pp. H408-H413 ◽  
Author(s):  
W. M. Armstead ◽  
C. W. Leffler ◽  
D. W. Busija ◽  
R. Mirro
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Metabolic Rate ◽  
Vascular Resistance ◽  
Brain Regions ◽  
Cerebral Metabolic Rate ◽  
Cerebral Vasoconstriction ◽  
Newborn Pigs ◽  
Cerebral Vascular Resistance ◽  
Cerebral Vascular

The interaction between vasopressinergic and prostanoid mechanisms in the control of cerebral hemodynamics in the conscious hypotensive newborn pig was investigated. Indomethacin treatment (5 mg/kg) of hypotensive piglets caused a significant decrease in blood flow to all brain regions within 20 min. This decrease in cerebral blood flow resulted from increased cerebral vascular resistances of 52 and 198% 20 and 40 min after treatment, respectively. Cerebral oxygen consumption was reduced from 2.58 +/- 0.32 ml.100 g-1.min-1 to 1.01 +/- 0.12 and 0.29 +/- 0.08 ml.100 g-1.min-1 20 and 40 min after indomethacin, respectively, in hemorrhaged piglets. Treatment with the putative vascular (V1) receptor antagonist [1-(beta-mercapto-beta, beta-cyclopentamethylene propionic acid-2-(O-methyl)tyrosine]arginine vasopressin (MEAVP) had no effect on regional cerebral blood flow, calculated cerebral vascular resistance, or cerebral metabolic rate either before or during hemorrhagic hypotension. However, decreases in cerebral blood flow and metabolic rate and increases in vascular resistance on treatment with indomethacin were blunted markedly in animals treated with MEAVP. These data are consistent with the hypothesis that the prostanoid system contributes to the maintenance of cerebral blood flow and cerebral metabolic rate during hypotension in the newborn pig, as reported previously, and implicate removal of vasopressinergic modulation by prostanoids as a potential mechanism for indomethacin-induced cerebral vasoconstriction in hypotensive newborn piglets.

scholarly journals Acute hypoxia increases the cerebral metabolic rate – a magnetic resonance imaging study

2015 ◽  
Vol 36 (6) ◽  
pp. 1046-1058 ◽  
Author(s):  
Mark B Vestergaard ◽  
Ulrich Lindberg ◽  
Niels Jacob Aachmann-Andersen ◽  
Kristian Lisbjerg ◽  
Søren Just Christensen ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Magnetic Resonance ◽  
Metabolic Rate ◽  
Oxygen Saturation ◽  
Healthy Subjects ◽  
Acute Hypoxia ◽  
Resonance Imaging ◽  
Cerebral Metabolic Rate

The aim of the present study was to examine changes in cerebral metabolism by magnetic resonance imaging of healthy subjects during inhalation of 10% O2 hypoxic air. Hypoxic exposure elevates cerebral perfusion, but its effect on energy metabolism has been less investigated. Magnetic resonance imaging techniques were used to measure global cerebral blood flow and the venous oxygen saturation in the sagittal sinus. Global cerebral metabolic rate of oxygen was quantified from cerebral blood flow and arteriovenous oxygen saturation difference. Concentrations of lactate, glutamate, N-acetylaspartate, creatine and phosphocreatine were measured in the visual cortex by magnetic resonance spectroscopy. Twenty-three young healthy males were scanned for 60 min during normoxia, followed by 40 min of breathing hypoxic air. Inhalation of hypoxic air resulted in an increase in cerebral blood flow of 15.5% ( p = 0.058), and an increase in cerebral metabolic rate of oxygen of 8.5% ( p = 0.035). Cerebral lactate concentration increased by 180.3% ([Formula: see text]), glutamate increased by 4.7% ([Formula: see text]) and creatine and phosphocreatine decreased by 15.2% ( p[Formula: see text]). The N-acetylaspartate concentration was unchanged ( p = 0.36). In conclusion, acute hypoxia in healthy subjects increased perfusion and metabolic rate, which could represent an increase in neuronal activity. We conclude that marked changes in brain homeostasis occur in the healthy human brain during exposure to acute hypoxia.

scholarly journals Cerebral Effects of Propofol following Bolus Administration in Sheep

1996 ◽  
Vol 24 (1) ◽  
pp. 26-31 ◽  
Author(s):  
G. L. Ludbrook ◽  
R. N. Upton ◽  
C. Grant ◽  
E. C. Gray
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Metabolic Rate ◽  
Electrical Stimulus ◽  
Bolus Administration ◽  
Depth Of Anaesthesia ◽  
Cerebral Metabolic Rate ◽  
Deep Anaesthesia ◽  
Dose Dependent ◽  
Withdrawal Response

The effects of bolus administration of propofol (50 mg, 100 mg and 200 mg) on cerebral blood flow and cerebral metabolic rate for oxygen were examined in a chronically catheterized sheep preparation. Depth of anaesthesia was simultaneously measured using a withdrawal response to a noxious electrical stimulus and it was demonstrated that the 100 mg dose induced moderate sedation while the 200 mg dose induced relatively deep anaesthesia. Propofol caused transient dose-dependent decreases in cerebral blood flow, despite minimal changes in blood pressure. These were accompanied by parallel decreases in cerebral metabolic rate but no change in cerebral oxygen extraction. As cerebrovascular responses in the sheep appear similar to those in man, the parallel changes in cerebral blood flow and metabolic rate demonstrated in this study supports the suitability of propofol as a neuroanaesthetic agent.

Effects of NMDA receptor glycine recognition site antagonism on cerebral metabolic rate for glucose and cerebral blood flow in the conscious rat

1998 ◽  
Vol 779 (1-2) ◽  
pp. 170-176 ◽  
Author(s):  
Yuji Morimoto ◽  
Bo Wu ◽  
Robert D Bart ◽  
Yoshiko Morimoto ◽  
Robert D Pearlstein ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Nmda Receptor ◽  
Metabolic Rate ◽  
Recognition Site ◽  
Conscious Rat ◽  
Cerebral Metabolic Rate

Hypothermia reduces cerebral metabolic rate and cerebral blood flow in newborn pigs

1987 ◽  
Vol 253 (4) ◽  
pp. H869-H873 ◽  
Author(s):  
D. W. Busija ◽  
C. W. Leffler
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Rectal Temperature ◽  
Cerebral Circulation ◽  
Radioactive Microspheres ◽  
Cerebrovascular Resistance ◽  
Cerebral Metabolic Rate ◽  
Newborn Pigs

We examined effects of hypothermia on cerebral metabolic rate and cerebral blood flow in anesthetized, newborn pigs (1-4 days old). Cerebral blood flow (CBF) was determined with 15-micronS radioactive microspheres. Regional CBF ranged from 44 to 66 ml . min-1.100 g-1, and cerebral metabolic rate was 1.94 +/- 0.23 ml O2.100 g-1 . min-1 during normothermia (39 degrees C). Reduction of rectal temperature to 34-35 degrees C decreased CBF and cerebral metabolic rate 40-50%. In another group of piglets, we examined responsiveness of the cerebral circulation to arterial hypercapnia during hypothermia. Although absolute values for normocapnic and hypercapnic CBF were reduced by hypothermia and absolute values for normocapnic and hypercapnic cerebrovascular resistance were increased, the percentage changes from control in these variables during hypercapnia were similar during normothermia and hypothermia. In another group of animals that were maintained normothermic and exposed to two episodes of hypercapnia, there was no attenuation of cerebrovascular dilatation during the second episode. We conclude that hypothermia reduces CBF secondarily to a decrease in cerebral metabolic rate and that percent dilator responsiveness to arterial hypercapnia is unaltered when body temperature is reduced.

scholarly journals The Role of Adenosine in Regulation of Cerebral Blood Flow During Hypoxia in the Near‐Term Fetal Sheep

2002 ◽  
Vol 543 (3) ◽  
pp. 1015-1023 ◽  
Author(s):  
Arlin B. Blood ◽  
Christian J. Hunter ◽  
Gordon G. Power
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Fetal Sheep ◽  
Near Term
Sign in / Sign up

Export Citation Format

Share Document