scholarly journals Fructose and Glucose Utilization by Lamb and Sheep Brain

1963 ◽  
Vol 16 (4) ◽  
pp. 922 ◽  
Author(s):  
BP Setchell
Keyword(s):  
Oxygen Uptake ◽  
Glucose Utilization ◽  
Brain Slices ◽  
Lactate Production ◽  
Mammalian Brain ◽  
Electrical Pulses ◽  
Sheep Brain

Fructose can be utilized by the mammalian brain in vitro as judged by oxygen uptake and by lactate production, although with some preparations lactate production was slower from fruotose than from gluoose (LoebeI1925; Diokens and Greville 1933; Edson and Leloir 1936; Geiger 1940; Klein 1944; Meyerhof and Wilson 1948). An increase in oxygen uptake by brain slices in vitro, during application of electrical pulses to the tissue, occurs when glucose is present in the medium; this also occurs when fructose is present in the medium, but higher concentrations of fructose than gluoose are needed for the same effeot (McIlwain 1953).

scholarly journals Imaging Subthreshold Voltage Oscillation With Cellular Resolution in the Inferior Olive in vitro

2020 ◽  
Vol 14 ◽  
Author(s):  
Kevin Dorgans ◽  
Bernd Kuhn ◽  
Marylka Yoe Uusisaari
Keyword(s):  
Inferior Olive ◽  
Brain Slices ◽  
Brain Regions ◽  
Mammalian Brain ◽  
Wide Field ◽  
Voltage Imaging ◽  
Subthreshold Oscillations ◽  
Cellular Resolution

Voltage imaging with cellular resolution in mammalian brain slices is still a challenging task. Here, we describe and validate a method for delivery of the voltage-sensitive dye ANNINE-6plus (A6+) into tissue for voltage imaging that results in higher signal-to-noise ratio (SNR) than conventional bath application methods. The not fully dissolved dye was injected into the inferior olive (IO) 0, 1, or 7 days prior to acute slice preparation using stereotactic surgery. We find that the voltage imaging improves after an extended incubation period in vivo in terms of labeled volume, homogeneous neuropil labeling with saliently labeled somata, and SNR. Preparing acute slices 7 days after the dye injection, the SNR is high enough to allow single-trial recording of IO subthreshold oscillations using wide-field (network-level) as well as high-magnification (single-cell level) voltage imaging with a CMOS camera. This method is easily adaptable to other brain regions where genetically-encoded voltage sensors are prohibitively difficult to use and where an ultrafast, pure electrochromic sensor, like A6+, is required. Due to the long-lasting staining demonstrated here, the method can be combined, for example, with deep-brain imaging using implantable GRIN lenses.

scholarly journals Thick Brain Slices Model the Ischemic Penumbra

1988 ◽  
Vol 8 (4) ◽  
pp. 586-597 ◽  
Author(s):  
George C. Newman ◽  
Frank E. Hospod ◽  
Priscilla Wu
Keyword(s):  
Glucose Utilization ◽  
Anaerobic Metabolism ◽  
Brain Slices ◽  
Ischemic Injury ◽  
Progressive Increase ◽  
Glycolytic Flux ◽  
Metabolic Profiles ◽  
Ischemic Penumbra ◽  
Morphologic Changes

Hypothalamic brain slices, varying in thickness from 400μ to 1,000μ, were assessed by studying 2-deoxyglucose (2DG) metabolism, lactate accumulation, inulin spaces, and morphology at the light and ultrastructural levels. Evidence of increased glycolytic flux due to anaerobic metabolism is found at thicknesses greater than 600μ in association with a progressive increase in the inulin-exclusion space. The metabolic profiles, as a function of depth into the slices, reveal that 700-μ slices function in a manner similar to 540-μ slices at the surfaces, but with a core of increased 2DG phosphorylation at the slice center. In contrast, the 1000-μ slices show significant reductions of 2DG and increases in 2DG6P relative to the 540-μ slices at the slice surface as well as in the slice interior, suggesting impaired transport of 2DG into cells and spread of ischemic injury from the slice interior to the slice surface. Despite these metabolic changes, only minor morphologic changes of ischemic injury were found at the center of thicker slices, and in vitro glucose utilization of 1000-μ slices remained constant for up to 15 h. These three slice thicknesses should provide a useful model for studying the neurochemistry and neuropharmacology of the ischemic penumbra.

Effects of indomethacin on energy metabolism in rat and human jejunal tissue in vitro

2001 ◽  
Vol 101 (5) ◽  
pp. 493-498 ◽  
Author(s):  
Molly JACOB ◽  
Ingvar BJARNASON ◽  
Robert J. SIMPSON
Keyword(s):  
Energy Metabolism ◽  
Oxygen Uptake ◽  
Energy Charge ◽  
Lactate Production ◽  
Inhibitory Effect ◽  
Mitochondrial Morphology ◽  
Rat Jejunum ◽  
Drug Concentrations ◽  
Inflammatory Drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are known to cause enteropathy, but the mechanism by which this toxicity occurs is less well established. This paper sets out to test the hypothesis that these drugs affect oxidative phosphorylation in jejunal tissue, thereby interfering with energy metabolism and rendering the tissue vulnerable to damage. Jejunal tissue obtained from rats and humans was used for in vitro determinations of oxygen uptake, lactate production and energy charge levels in the presence of indomethacin, a commonly used NSAID. In the rat jejunal tissue, drug concentrations of 0.5mM and 2.5mM produced significant decreases in oxygen uptake (P < 0.01) and energy charge levels in the tissue (P < 0.05). There was a corresponding increase in lactate production by the tissue at these indomethacin concentrations (P < 0.05). Rat jejunum examined by electron microscopy after incubation with various concentrations of indomethacin showed ultrastructural effects of the drug on mitochondrial morphology. In human tissue, an inhibitory effect of indomethacin on oxygen uptake was seen, but the effects on lactate production and energy charge were less conclusive. These findings suggest that indomethacin affects mitochondria and thereby impairs energy metabolism in jejunal tissue.

scholarly journals Kinetic Model of 2-Deoxyglucose Metabolism Using Brain Slices

1990 ◽  
Vol 10 (4) ◽  
pp. 510-526 ◽  
Author(s):  
George C. Newman ◽  
Frank E. Hospod ◽  
Clifford S. Patlak
Keyword(s):  
Kinetic Model ◽  
Rate Constants ◽  
Glucose Utilization ◽  
Brain Slices ◽  
Nonlinear Least Squares ◽  
Relative Importance ◽  
Derived Data ◽  
Single Reaction

A six-compartment, nine-parameter kinetic model of 2-deoxyglucose (2DG) metabolism, which includes bidirectional tissue transport, phosphorylation, two-step dephosphorylation, phosphoisomerization, and conjugation to UDP and macromolecules, has been derived. Data for analysis were obtained from 540- and 1,000-μm-thick hippocampal and hypothalamic brain slices, which were incubated in buffer containing [14C]2DG, frozen, extracted with perchlorate, and separated on anion-exchange columns. Solutions of the equations of the model were fit to the data by means of nonlinear least-squares analysis. These studies suggest that dephosphorylation is adequately described by a single reaction so that the model reduces to eight parameters. The in vitro rate constants for transport, phosphorylation, and dephosphorylation are very similar to prior in vivo results. The phosphoisomerization rate constant is similar to dephosphorylation, so glycosylated macromolecules slowly accumulate and gradually assume larger relative importance as other compounds disappear more rapidly. Rate constants for 540-μm slices from hypothalamus and hippocampus are similar, while 1,000-μm slices have smaller tissue transport constants and larger phosphorylation constants. The rate equation for glucose utilization of this model is relatively insensitive to uncertainties regarding the rate constants. Including later metabolic components in kinetic models improves the calculations of glucose utilization with long isotope exposures.

Effect of osmolality on glucose metabolism in rabbit kidney cortex and medulla in vitro

1964 ◽  
Vol 207 (2) ◽  
pp. 473-482 ◽  
Author(s):  
James B. Lee ◽  
Vernon K. Vance ◽  
George F. Cahill
Keyword(s):  
Glucose Metabolism ◽  
Glucose Oxidation ◽  
Glucose Utilization ◽  
Lactate Production ◽  
Rabbit Kidney ◽  
Kidney Cortex ◽  
Osmotic Gradient ◽  
Cortical Slice ◽  
Kidney Medulla

Slices of rabbit kidney cortex and medulla were incubated aerobically in media of varying osmotic concentrations. When medium osmolality was reduced below 280–300 mosmoles/kg H2O, by means of decreased sodium chloride and sucrose concentrations, there was an osmotically determined increase in cortical glucose utilization and oxidation, lactate production, and slice weight. Between 280 and 300 mosmoles/kg H2O maximal cortical slice weight loss and inhibition of glucose metabolism occurred, with little further change when medium osmolality was increased to 415 mosmoles/kg H2O. With urea, slice weight and relatively maximal glucose metabolism were maintained at all medium osmotic concentrations between 67 and 548 mosmoles/kg H2O. In contrast, slices of kidney medulla revealed a capacity for extensive glucose oxidation in hyperosmotic media (1,066 mosmoles/kg H2O), while maximal lactate production occurred in hypoosmotic media (67 mosmoles/kg H2O). The findings are interpreted as suggestive of responsiveness of cortical and medullary intermediary metabolism to changes in the "effective" extracellular-to-intracellular osmotic gradient.

Endogenous oxygen uptake of the hypothalamus in female rats

1964 ◽  
Vol 206 (4) ◽  
pp. 855-857 ◽  
Author(s):  
J. A. Moguilevsky ◽  
M. R. Malinow
Keyword(s):  
Oxygen Uptake ◽  
Brain Slices ◽  
Female Rats ◽  
The Brain

The endogenous oxygen uptake has been determined in the hypothalamus, brain, hypophysis, and uterus of female rats. With the exception of the brain, similar changes have been detected in connection with estrous phases in all of these organs: lower respiratory rates were observed during diestrus and higher ones during estrus. Estradiol and progesterone were added in vitro to hypothalamus and brain slices of estrous and diestrous rats. Although both hormones consistently depressed the Qo2 in brain, such effects were seen only in the hypothalamus of estrous animals.

scholarly journals Ischemic Brain Slice Glucose Utilization: Effects of Slice Thickness, Acidosis, and K+

1991 ◽  
Vol 11 (3) ◽  
pp. 398-406 ◽  
Author(s):  
George C. Newman ◽  
Frank E. Hospod ◽  
Scott L. Schissel
Keyword(s):  
Brain Slice ◽  
Glucose Utilization ◽  
Brain Slices ◽  
Slice Thickness ◽  
Energy Demands ◽  
High K ◽  
Metabolic Products ◽  
Glucose Phosphorylation ◽  
Vitro Model

Brain slices of varying thickness were used to modify retention of metabolic products in an in vitro model of ischemia. Past and present results reveal increased anaerobic glycolysis in 660-μm slices with accumulation of lactate as slice thickness reaches 1,000 μm. Brain slice glucose utilization and lactate content were measured in buffers of various extracellular K+ levels and pH in 540-, 660-, and 1,000-μm slices. Acidosis suppresses glucose utilization at all slice thicknesses without affecting tissue lactate. Studies of 2-deoxyglucose metabolites establish that the suppression of glucose utilization by acidosis is due entirely to inhibition of glucose phosphorylation without any effect on glucose uptake into tissue. The inhibition is reversible after 45 min at pH 6.1. The experiments with acidosis also suggest that persistent energy demands continue to stimulate phosphofructokinase despite the low pH so that glycolysis continues, with potential for injury. Increasing K+ increases glucose utilization and tissue lactate at all three thicknesses. Correlations of glucose utilization with lactate accumulation support the possibility that high K+ may exert a dual influence on the tissue metabolism, not only stimulating glucose utilization by inducing depolarization but also by influencing the removal of metabolic products.

Platelet Metabolism in Alcohol-related Thrombocytopenia

1974 ◽  
Vol 31 (01) ◽  
pp. 149-159 ◽  
Author(s):  
Dale H Cowan
Keyword(s):  
Carbohydrate Metabolism ◽  
Energy Production ◽  
Glucose Oxidation ◽  
Glucose Utilization ◽  
Metabolic Response ◽  
Lactate Production ◽  
Metabolic Responses ◽  
Platelet Dysfunction ◽  
14Co2 Production

SummaryThe carbohydrate metabolism of platelets from patients with alcohol-related thrombocytopenia was studied. Rates of utilization and oxidation of 14C-glueose, 14C-lactate production, and pentose cycle activity were measured in resting platelets and in platelets stimulated with thrombin or epinephrine. The metabolism of resting platelets from patients with alcohol-related thrombocytopenia was normal but the metabolic responses to stimulation differed from normal : stimulation with thrombin was associated with subnormal 14C-lactate production and normal 14CO2 production and that with epinephrine was associated with normal 14C-lactate production and subnormal 14CO2 production. Addition of ethanol to normal platelets in vitro produced increases in 14C-glucose utilization and 14C-lactate production but not in 14C-glucose oxidation. Ethanol added to normal platelets in vitro did not affect the metabolic response to thrombin stimulation but produced a 50% reduction in the response to epinephrine. Platelet dysfunction in patients with alcohol-related thrombocytopenia is not due to quantitative abnormalities in platelet energy production. Ethanol appears, however, to alter the metabolic response to nucleotide release and degradation.

scholarly journals Lactate utilization by the neonatal rat brain in vitro. Competition with glucose and 3-hydroxybutyrate

1986 ◽  
Vol 234 (2) ◽  
pp. 489-492 ◽  
Author(s):  
E Fernández ◽  
J M Medina
Keyword(s):  
Rat Brain ◽  
Glucose Utilization ◽  
Brain Slices ◽  
Neonatal Rat ◽  
Neonatal Brain ◽  
Lactate Oxidation ◽  
Inhibited Oxidation ◽  
Lactate Utilization ◽  
Neonatal Rat Brain

The maximum rates of lactate oxidation and lipogenesis from lactate by early-neonatal brain slices were considerably greater than those for utilization of glucose and 3-hydroxybutyrate at physiological concentrations. Lactate inhibited glucose utilization, but enhanced 3-hydroxybutyrate utilization. 3-Hydroxybutyrate inhibited lactate and glucose utilization. Glucose slightly inhibited oxidation of lactate and 3-hydroxybutyrate, but scarcely enhanced lipogenesis from these substrates.

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