scholarly journals Effect of Ischemia and Reperfusion on λ of the Lumped Constant of the [14C]Deoxyglucose Technique

1992 ◽  
Vol 12 (1) ◽  
pp. 70-77 ◽  
Author(s):  
Joel H. Greenberg ◽  
Janos Hamar ◽  
Frank A. Welsh ◽  
Valerie Harris ◽  
Martin Reivich
Keyword(s):  
Cerebral Ischemia ◽  
Glucose Metabolism ◽  
Glucose Concentration ◽  
Focal Cerebral Ischemia ◽  
Ischemia And Reperfusion ◽  
Similar Relationship ◽  
Arterial Blood ◽  
Lumped Constant ◽  
Distribution Spaces ◽  
The Brain

We measured the parameter λ, which is the ratio of the distribution spaces of 2-deoxy-d-glucose (DG) and glucose in the brain, in a model of focal cerebral ischemia in the cat. λ is the parameter in the lumped constant of the [14C]DG technique most susceptible to changes in ischemia. Cats were subjected to occlusion of the middle cerebral artery for a period of 2 h. During the last 60 min of occlusion, [14C]DG was infused in a programmed fashion so as to obtain a stable arterial blood [14C]DG concentration. The brain was funnel-frozen to preserve tissue metabolites and the frozen brain was sampled regionally (4 to 7-mg samples) for local concentrations of glucose, ATP, phosphocreatine (PCr), and lactate. In a separate series of cats, the infusion of [14C]DG was started after 2 h of occlusion and 3 h of recirculation. In both series, λ declined slightly for increased levels of tissue glucose and increased appreciably as tissue glucose decreased. A similar relationship was observed between λ and ATP and PCr, although the correlation was not as clear. Since λ, and hence the lumped constant, increases in ischemia as well as in postischemic tissue, it is important to measure tissue glucose concentration if quantitative values of local cerebral glucose metabolism are desired in this condition.

scholarly journals Direct Measurement of the λ of the Lumped Constant of the Deoxyglucose Method in Rat Brain: Determination of λ and Lumped Constant from Tissue Glucose Concentration or Equilibrium Brain/Plasma Distribution Ratio for Methylglucose

1991 ◽  
Vol 11 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Gerald A. Dienel ◽  
Nancy F. Cruz ◽  
Kentaro Mori ◽  
James E. Holden ◽  
Louis Sokoloff
Keyword(s):  
Plasma Glucose ◽  
Glucose Concentration ◽  
Full Range ◽  
Acid Extraction ◽  
Distribution Space ◽  
Glucose Levels ◽  
Lumped Constant ◽  
Distribution Spaces ◽  
The Brain

Steady-state distribution spaces of 2-[14C]deoxyglucose ([14C]DG), glucose, and 3- O-[14C]methylglucose at various concentrations of glucose in brain and plasma ranging from hypoglycemic to hyperglycemic levels have been determined by direct chemical analyses in the brains of conscious rats. The hexose concentrations were measured chemically in freeze-blown brain extracted with ethanol to avoid the degradation of acid-labile products of [14C]DG back to free [14C]DG that has been found to occur with the more commonly used perchloric acid extraction of brain. Corrections were also made for nonphosphorylatable, labeled products of [14C]DG found in the nonacidic fractions of the brain extracts, which were previously included with the assayed [14C]DG, and for the contribution of the hexose contents in the blood in the brain, which was found to be particularly critical for the determination of the glucose distribution space, especially in hypoglycemic states. From the measured contents of the hexoses in brain and plasma, the relationships of the tissue concentrations and distribution spaces of each of the hexoses and of the Λ (i.e., ratio of tissue distribution space of DG to that of glucose) of the DG method to the tissue glucose concentration were derived. The Λ was then quantitatively related to the measured equilibrium ratio for [14C]methylglucose over the full range of brain and plasma glucose levels. By combining these new data with the values for the lumped constant, the factor that converts rate of DG phosphorylation to glucose phosphorylation, previously determined in rats over the same range of plasma glucose levels, the phosphorylation coefficient was calculated and the lumped constant graphed as a function of the measured distribution space in brain for [14C]methylglucose.

scholarly journals Direct Chemical Measurement of the λ of the Lumped Constant of the [14C]Deoxyglucose Method in Rat Brain: Effects of Arterial Plasma Glucose Level on the Distribution Spaces of [14C]Deoxyglucose and Glucose and on λ

1989 ◽  
Vol 9 (3) ◽  
pp. 304-314 ◽  
Author(s):  
Kentaro Mori ◽  
Nancy Cruz ◽  
Gerald Dienel ◽  
Thomas Nelson ◽  
Louis Sokoloff
Keyword(s):  
Plasma Glucose ◽  
Glucose Concentration ◽  
Severe Hypoglycemia ◽  
Plasma Glucose Concentration ◽  
Operational Equation ◽  
Chemical Measurements ◽  
Lumped Constant ◽  
Dg Method ◽  
Arterial Plasma ◽  
Distribution Spaces

The lumped constant in the operational equation of the 2-[14C]deoxyglucose (DG) method contains the factor λ that represents the ratio of the steady-state tissue distribution spaces for [14C]DG and glucose. The lumped constant has been shown to vary with arterial plasma glucose concentration. Predictions based mainly on theoretical grounds have suggested that disproportionate changes in the distribution spaces for [14C]DG and glucose and in the value of λ are responsible for these variations in the lumped constant. The influence of arterial plasma glucose concentration on the distribution spaces for DG and glucose and on λ were, therefore, determined in the present studies by direct chemical measurements. The brain was maintained in steady states of delivery and metabolism of DG and glucose by programmed intravenous infusions of both hexoses designed to produce and maintain constant arterial concentrations. Hexose concentrations were assayed in acid extracts of arterial plasma and freeze-blown brain. Graded hyperglycemia up to 28 m M produced progressive decreases in the distribution spaces of both hexoses from their normoglycemic values (e.g., ∼ – 20% for glucose and – 50% for DG at 28 m M). In contrast, graded hypoglycemia progressively reduced the distribution space for glucose and increased the space for [14C]DG. The values for λ were comparatively stable in normoglycemic and hyperglycemic conditions but rose sharply (e.g., as much as 9–10-fold at 2 m M) in severe hypoglycemia.

scholarly journals Zingiber officinaleMitigates Brain Damage and Improves Memory Impairment in Focal Cerebral Ischemic Rat

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Jintanaporn Wattanathorn ◽  
Jinatta Jittiwat ◽  
Terdthai Tongun ◽  
Supaporn Muchimapura ◽  
Kornkanok Ingkaninan
Keyword(s):  
Cognitive Function ◽  
Cerebral Ischemia ◽  
Brain Damage ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Neuroprotective Effect ◽  
Morris Water Maze Test ◽  
Brain Infarct ◽  
Ginger Rhizome ◽  
The Brain

Cerebral ischemia is known to produce brain damage and related behavioral deficits including memory. Recently, accumulating lines of evidence showed that dietary enrichment with nutritional antioxidants could reduce brain damage and improve cognitive function. In this study, possible protective effect ofZingiber officinale, a medicinal plant reputed for neuroprotective effect against oxidative stress-related brain damage, on brain damage and memory deficit induced by focal cerebral ischemia was elucidated. Male adult Wistar rats were administrated an alcoholic extract of ginger rhizome orally 14 days before and 21 days after the permanent occlusion of right middle cerebral artery (MCAO). Cognitive function assessment was performed at 7, 14, and 21 days after MCAO using the Morris water maze test. The brain infarct volume and density of neurons in hippocampus were also determined. Furthermore, the level of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in cerebral cortex, striatum, and hippocampus was also quantified at the end of experiment. The results showed that cognitive function and neurons density in hippocampus of rats receiving ginger rhizome extract were improved while the brain infarct volume was decreased. The cognitive enhancing effect and neuroprotective effect occurred partly via the antioxidant activity of the extract. In conclusion, our study demonstrated the beneficial effect of ginger rhizome to protect against focal cerebral ischemia.

Biochemical Effects of Cerebral Ischemia: Relevance To Migraine

Cephalalgia ◽  
1985 ◽  
Vol 5 (2_suppl) ◽  
pp. 35-42 ◽  
Author(s):  
KMA Welch ◽  
JA Helpern ◽  
JR Ewing ◽  
WM Robertson ◽  
G D'Andrea
Keyword(s):  
Energy Metabolism ◽  
Cerebral Ischemia ◽  
Spreading Depression ◽  
Metabolic Depression ◽  
Ischemia And Reperfusion ◽  
Phosphate Metabolism ◽  
Biochemical Effects ◽  
The Brain ◽  
Intracranial Circulation

Although decreased CBF has now been reported during the prodrome of migraine, the cause of the decreased flow is still unknown. It is particularly unclear whether these phenomena are related to vasospasm and “steal” between the extracranial and intracranial circulation or to the spreading depression of Leao and the accompanying metabolic depression. In the present paper, metabolic changes in the brain during ischemia and reperfusion are reviewed and compared with CNS biochemical changes during migraine attack. In addition, the technique of Topical Magnetic Resonance (TMR) as applied to the in vivo study of energy phosphate metabolism in extracranial tissues and brain is described and the potential of this technique to evaluate shifts in energy metabolism and pH in stroke and migraine is discussed.

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