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.

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.

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 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.

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.

Effect of ornidazole on fertility of male rats: inhibition of a glycolysis-related motility pattern and zona binding required for fertilization in vitro

Reproduction ◽  
2000 ◽  
pp. 127-135 ◽  
Author(s):  
W Bone ◽  
NG Jones ◽  
G Kamp ◽  
CH Yeung ◽  
TG Cooper
Keyword(s):  
Zona Pellucida ◽  
Glucose Utilization ◽  
Cumulus Cells ◽  
Glycolytic Enzyme ◽  
Male Rats ◽  
Fertilization In Vitro ◽  
Swimming Pattern ◽  
Principal Piece ◽  
Free Media

The effects of the male antifertility agent ornidazole on glycolysis as a prerequisite for fertilization were investigated in rats. Antifertility doses of ornidazole inhibited glycolysis within mature spermatozoa as determined from the lack of glucose utilization, reduced acidosis under anaerobic conditions and reduced glycolytic enzyme activity. As a consequence, cauda epididymidal spermatozoa from ornidazole-fed rats were unable to fertilize rat oocytes in vitro, with or without cumulus cells, which was not due to transfer of an inhibitor in epididymal fluid with the spermatozoa. Under IVF conditions, binding to the zona pellucida was reduced in spermatozoa from ornidazole-fed males and the spermatozoa did not undergo a change in swimming pattern, which was observed in controls. The block to fertilization could be explained by the disruption of glycolysis-dependent events, since reduced binding to the zona pellucida and a lack of kinematic changes were demonstrated by control spermatozoa in glucose-free media in the presence of respiratory substrates. The importance of glycolysis for binding to, and penetration of, the zona pellucida, and hyperactivation in rats is discussed in relation to the glycolytic production of ATP in the principal piece in which local deprivation of energy may explain the reduced force of spermatozoa from ornidazole-fed males.

In vitro autoregulation of glucose utilization in rat soleus muscle

Diabetes ◽  
1987 ◽  
Vol 36 (9) ◽  
pp. 1041-1046 ◽  
Author(s):  
S. Sasson ◽  
D. Edelson ◽  
E. Cerasi
Keyword(s):  
Soleus Muscle ◽  
Glucose Utilization ◽  
Rat Soleus Muscle

scholarly journals Preservation of Human Gut Microbiota Inoculums for In Vitro Fermentations Studies

Fermentation ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 14
Author(s):  
Nelson Mota de Carvalho ◽  
Diana Luazi Oliveira ◽  
Mayra Anton Dib Saleh ◽  
Manuela Pintado ◽  
Ana Raquel Madureira
Keyword(s):  
Gut Microbiota ◽  
Metabolic Profile ◽  
Bacterial Count ◽  
Glycerol Solution ◽  
Metabolic Profiles ◽  
Human Gut ◽  
Colonic Fermentation ◽  
In Vitro Fermentation ◽  
Fecal Samples

The use of fecal inoculums for in vitro fermentation models requires a viable gut microbiota, capable of fermenting the unabsorbed nutrients. Fresh samples from human donors are used; however, the availability of fresh fecal inoculum and its inherent variability is often a problem. This study aimed to optimize a method of preserving pooled human fecal samples for in vitro fermentation studies. Different conditions and times of storage at −20 °C were tested. In vitro fermentation experiments were carried out for both fresh and frozen inoculums, and the metabolic profile compared. In comparison with the fresh, the inoculum frozen in a PBS and 30% glycerol solution, had a significantly lower (p < 0.05) bacterial count (<1 log CFU/mL). However, no significant differences (p < 0.05) were found between the metabolic profiles after 48 h. Hence, a PBS and 30% glycerol solution can be used to maintain the gut microbiota viability during storage at −20 °C for at least 3 months, without interfering with the normal course of colonic fermentation.

scholarly journals A New Transgenic Mouse Line for Imaging Mitochondrial Calcium Signals

Function ◽  
2021 ◽  
Vol 2 (3) ◽  
Author(s):  
Nelly Redolfi ◽  
Elisa Greotti ◽  
Giulia Zanetti ◽  
Tino Hochepied ◽  
Cristina Fasolato ◽  
...  
Keyword(s):  
Transgenic Mouse ◽  
Fluorescent Protein ◽  
Ex Vivo ◽  
Brain Slices ◽  
Resonance Energy ◽  
Mouse Line ◽  
Isolated Cells ◽  
Genomic Locus ◽  
Transgenic Mouse Line

AbstractMitochondria play a key role in cellular calcium (Ca2+) homeostasis. Dysfunction in the organelle Ca2+ handling appears to be involved in several pathological conditions, ranging from neurodegenerative diseases, cardiac failure and malignant transformation. In the past years, several targeted green fluorescent protein (GFP)-based genetically encoded Ca2+ indicators (GECIs) have been developed to study Ca2+ dynamics inside mitochondria of living cells. Surprisingly, while there is a number of transgenic mice expressing different types of cytosolic GECIs, few examples are available expressing mitochondria-localized GECIs, and none of them exhibits adequate spatial resolution. Here we report the generation and characterization of a transgenic mouse line (hereafter called mt-Cam) for the controlled expression of a mitochondria-targeted, Förster resonance energy transfer (FRET)-based Cameleon, 4mtD3cpv. To achieve this goal, we engineered the mouse ROSA26 genomic locus by inserting the optimized sequence of 4mtD3cpv, preceded by a loxP-STOP-loxP sequence. The probe can be readily expressed in a tissue-specific manner upon Cre recombinase-mediated excision, obtainable with a single cross. Upon ubiquitous Cre expression, the Cameleon is specifically localized in the mitochondrial matrix of cells in all the organs and tissues analyzed, from embryos to aged animals. Ca2+ imaging experiments performed in vitro and ex vivo in brain slices confirmed the functionality of the probe in isolated cells and live tissues. This new transgenic mouse line allows the study of mitochondrial Ca2+ dynamics in different tissues with no invasive intervention (such as viral infection or electroporation), potentially allowing simple calibration of the fluorescent signals in terms of mitochondrial Ca2+ concentration ([Ca2+]).

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