scholarly journals INCREASE IN INCORPORATION OF INORGANIC PHOSPHATE-32 INTO PHOSPHATIDE ACID IN BRAIN SLICES BY OUABAIN, EDTA OR A HIGH CONCENTRATION OF POTASSIUM

1962 ◽  
Vol 12 (2) ◽  
pp. 156-162 ◽  
Author(s):  
HIROSHI YOSHIDA ◽  
HISAO FUJISAWA ◽  
TADAATSU NUKADA
Keyword(s):  
Inorganic Phosphate ◽  
Brain Slices ◽  
High Concentration ◽  
Phosphatide Acid

INCORPORATION OF RADIOACTIVE PHOSPHATE INTO NON-NUCLEOTIDE PROTEIN-BOUND PHOSPHORUS FRACTIONS OF RESPIRING CAT BRAIN SLICES

1954 ◽  
Vol 32 (1) ◽  
pp. 504-514
Author(s):  
Muriel Findlay ◽  
K. P. Strickland ◽  
R. J. Rossiter
Keyword(s):  
Inorganic Phosphate ◽  
Organic Phosphorus ◽  
Brain Slices ◽  
Phosphorus Fractions ◽  
Metabolic Inhibitors ◽  
Lipid Phosphorus ◽  
Wide Range ◽  
Cat Brain

Slices of cat brain respiring in a Krebs–Ringer bicarbonate medium were found to incorporate inorganic phosphate labelled with P32 into two non-nucleotide protein-bound phosphorus fractions, which are referred to as the residue organic phosphorus (ROP) and the "phosphoprotein" (PP), respectively. The addition of glucose or mannose to the medium increased the incorporation into both fractions. The addition of fructose, galactose, pyruvate, lactate, succinate, or L-glutamate failed to increase the incorporation into either fraction.Anaerobic conditions, homogenization of the tissue, or the addition of a wide range of metabolic inhibitors (cyanide, azide, iodoacetate, fluoride, nembutal, malononitrile, chloretone) inhibited the incorporation. The incorporation was also inhibited by 2,4-dinitrophenol in concentrations that do not inhibit oxygen consumption.These results are compared and contrasted with previous findings on the incorporation of P32 into the lipid phosphorus and pentosenucleic acid of brain slices.

INCORPORATION OF RADIOACTIVE PHOSPHATE INTO NON-NUCLEOTIDE PROTEIN-BOUND PHOSPHORUS FRACTIONS OF RESPIRING CAT BRAIN SLICES

1954 ◽  
Vol 32 (5) ◽  
pp. 504-514 ◽  
Author(s):  
Muriel Findlay ◽  
K. P. Strickland ◽  
R. J. Rossiter
Keyword(s):  
Inorganic Phosphate ◽  
Organic Phosphorus ◽  
Brain Slices ◽  
Phosphorus Fractions ◽  
Metabolic Inhibitors ◽  
Lipid Phosphorus ◽  
Wide Range ◽  
Cat Brain

Slices of cat brain respiring in a Krebs–Ringer bicarbonate medium were found to incorporate inorganic phosphate labelled with P32 into two non-nucleotide protein-bound phosphorus fractions, which are referred to as the residue organic phosphorus (ROP) and the "phosphoprotein" (PP), respectively. The addition of glucose or mannose to the medium increased the incorporation into both fractions. The addition of fructose, galactose, pyruvate, lactate, succinate, or L-glutamate failed to increase the incorporation into either fraction.Anaerobic conditions, homogenization of the tissue, or the addition of a wide range of metabolic inhibitors (cyanide, azide, iodoacetate, fluoride, nembutal, malononitrile, chloretone) inhibited the incorporation. The incorporation was also inhibited by 2,4-dinitrophenol in concentrations that do not inhibit oxygen consumption.These results are compared and contrasted with previous findings on the incorporation of P32 into the lipid phosphorus and pentosenucleic acid of brain slices.

scholarly journals Effects of tetrodotoxin and anaesthetics on brain metabolism and transport during anoxia

1972 ◽  
Vol 126 (4) ◽  
pp. 851-867 ◽  
Author(s):  
R. Shankar ◽  
J. H. Quastel
Keyword(s):  
Action Potentials ◽  
Brain Cortex ◽  
Aerobic Glycolysis ◽  
Rat Kidney ◽  
Brain Slices ◽  
Anaerobic Glycolysis ◽  
High Concentration ◽  
Adult Rats ◽  
Brain Cortex Slices ◽  
Cortex Slices

1. Tetrodotoxin, at concentrations at which it abolishes generation of action potentials in the nervous system, enhances by about 300% the rate of anaerobic glycolysis of brain-cortex slices from adult rats, or from adult and infant guinea pigs. This occurs to a greater extent in Ca2+-deficient incubation media than in Ca2+-rich media. Tetrodotoxin has no accelerative effect on cerebral aerobic glycolysis. 2. Tetrodotoxin does not affect the rate of anaerobic glycolysis of 2-day-old rat brain-cortex slices, nor that of adult rat kidney medulla, nor that of an extract of an acetone-dried powder of brain. 3. Tetrodotoxin does not affect the rate of penetration of glucose into brain slices. 4. Its effect is not apparent if it is added 10min or later after the onset of anoxia. 5. Its effect diminishes as the concentration of K+ in the incubation medium is increased while that of Na+ is decreased. 6. Its salient effect, at the onset of anoxia, is to diminish influx of Na+ into, and efflux of K+ from, the brain slices. 7. Substances that promote cerebral influx of Na+, e.g. protoveratrine, sodium l-glutamate, diminish the accelerative action of tetrodotoxin. 8. It is concluded that tetrodotoxin exerts its effect on anaerobic glycolysis by suppressing, at the onset of anoxia, the generation of action potentials and thereby the accompanying influx of Na+ and efflux of K+. It is suggested that glycolytic stimulation occurs because a rate-limiting step, e.g. operation of pyruvate kinase, is stimulated by K+ and depressed by Na+. 9. Local anaesthetics behave in a manner similar to that of tetrodotoxin in enhancing cerebral anaerobic glycolysis. 10. Sodium Amytal has a marked effect at relatively high concentration. 11. Tetrodotoxin diminishes efflux of amino acids, particularly glutamate and aspartate, at the onset of anoxia.

scholarly journals The interplay between inorganic phosphate and amino acids determines zinc solubility in brain slices

2009 ◽  
Vol 108 (5) ◽  
pp. 1300-1308 ◽  
Author(s):  
Sean M. Rumschik ◽  
Irma Nydegger ◽  
Jinfu Zhao ◽  
Alan R. Kay
Keyword(s):  
Amino Acids ◽  
Inorganic Phosphate ◽  
Brain Slices

EFFECTS OF SODIUM-FREE MEDIA UPON THE METABOLISM AND THE POTASSIUM AND WATER CONTENTS OF BRAIN SLICES

1958 ◽  
Vol 36 (1) ◽  
pp. 217-226 ◽  
Author(s):  
Hanna M. Pappius ◽  
M. Rosenfeld ◽  
Dorothy McLean Johnson ◽  
K. A. C. Elliott
Keyword(s):  
Oxygen Uptake ◽  
Brain Slices ◽  
Anaerobic Glycolysis ◽  
Anaerobic Conditions ◽  
High Concentration ◽  
Intracellular Space ◽  
Low Potassium ◽  
Free Media ◽  
Water Contents ◽  
Slight Inhibition

Brain slices maintain a high concentration of potassium when incubated aerobically in ordinary sodium-containing low-potassium medium but the concentration falls to the level found under plain anaerobic conditions if choline, lithium, or tris-(hydroxymethyl)-aminomethane (tris) are substituted for all the sodium in the medium. With the choline medium, concentration of potassium in the tissue increases markedly if a very little sodium is present; considerably more sodium is required when the main cation present is lithium. A moderately high concentration of potassium is maintained in tissue under anaerobic conditions in sodium-containing medium when glycolysis is stimulated by pyruvate and previous aerobiosis. This high concentration is not found when sodium in the medium is replaced by choline or lithium. The potassium content of slices incubated aerobically or anaerobically with potassium replacing all sodium in the medium is higher than could be accounted for by simple equilibration of the slice fluids with the medium.The rate of oxygen uptake is not changed when choline or lithium replace all the sodium in the medium; with tris or potassium in place of sodium there is slight inhibition. Anaerobic glycolysis is increased in the choline and potassium media and slightly depressed in lithium medium. The stimulatory effect on anaerobic glycolysis of pyruvate is apparent in the sodium, choline, lithium, and potassium media but the stimulation by a preliminary period of aerobiosis does not occur in the lithium and potassium media.Under aerobic conditions swelling and "intracellular" (non-sucrose) space is not affected by replacing sodium with choline or lithium. Both are increased in the tris and, especially, in the potassium media. Under anaerobic conditions there is a striking decrease in swelling and intracellular space with the choline medium.The replacement of a small amount of salt by sucrose causes a decrease in swelling in all media, especially in the potassium medium.

FACTORS AFFECTING THE INCORPORATION OF RADIOACTIVE PHOSPHATE INTO THE PHOSPHOLIPIDS OF SLICES OF CAT BRAIN

1954 ◽  
Vol 32 (1) ◽  
pp. 50-59 ◽  
Author(s):  
K. P. Strickland
Keyword(s):  
Oxygen Consumption ◽  
Inorganic Phosphate ◽  
Brain Slices ◽  
Phospholipid Fraction ◽  
Metabolic Inhibitors ◽  
Factors Affecting ◽  
Wide Range ◽  
Cat Brain

Slices of cat brain respiring in a Krebs–Ringer bicarbonate medium were found to incorporate radioactive inorganic phosphate (P32) into the phospholipid fraction. The addition of glucose or mannose increased the incorporation of P32 into the phospholipids. Fructose caused a small increase, whereas galactose was without effect. Pyruvate and lactate increased the incorporation of P32 into the phospholipids. Succinate, L (+)-glutamate, D (−)-glutamate, α keto-glutarate, citrate, and L-malate failed to support the incorporation.Anaerobic conditions and homogenization of the tissue prevented the in vitro incorporation of P32 into the phospholipids of cat brain. A wide range of metabolic inhibitors (cyanide, azide, malononitrile, chloretone, nembutal, iodoacetate, and fluoride), in concentrations that inhibit the oxygen consumption of brain slices, inhibited the incorporation. The incorporation was also inhibited by 2,4-dinitrophenol in concentrations that do not decrease the oxygen consumption of brain slices.These findings indicated that the incorporation of P32 into the phospholipids of slices of cat brain is a metabolic phenomenon and is dependent upon the maintenance of an adequate phosphorylating mechanism within the slice.

Metabolic fate of a high concentration of glutamine and glutamate in rat brain slices: A 13C NMR study

2011 ◽  
Vol 58 (8) ◽  
pp. 896-903 ◽  
Author(s):  
Maha El Hage ◽  
Agnès Conjard-Duplany ◽  
Gabriel Baverel ◽  
Guy Martin
Keyword(s):  
Rat Brain ◽  
13C Nmr ◽  
Brain Slices ◽  
Metabolic Fate ◽  
High Concentration ◽  
Nmr Study

scholarly journals Excitatory GABAergic signalling is associated with acquired benzodiazepine resistance in status epilepticus

2018 ◽  
Author(s):  
Richard J. Burman ◽  
Joshua S. Selfe ◽  
John Hamin Lee ◽  
Maurits van den Burg ◽  
Alexandru Calin ◽  
...  
Keyword(s):  
Status Epilepticus ◽  
Epileptiform Activity ◽  
Brain Slices ◽  
Medical Emergency ◽  
Dependent Manner ◽  
High Concentration ◽  
Cellular Mechanisms ◽  
Epileptiform Discharges ◽  
Threatening Condition ◽  
Eeg Recordings

AbstractStatus epilepticus (SE) is defined as a state of unrelenting seizure activity. Generalised convulsive SE is associated with a rapidly rising mortality rate, and thus constitutes a medical emergency. Benzodiazepines, which act as positive modulators of chloride (Cl-) permeable GABAA receptors, are indicated as first-line treatment, but this is ineffective in many cases. We found that 48% of children presenting with SE were unresponsive to benzodiazepine treatment, and critically, that the duration of SE at the time of treatment is an important predictor of non-responsiveness. We therefore investigated the cellular mechanisms that underlie acquired benzodiazepine resistance, using rodent organotypic and acute brain slices. Removing Mg2+ ions leads to an evolving pattern of epileptiform activity, and eventually to a persistent state of repetitive discharges that strongly resembles clinical EEG recordings of SE. We found that diazepam loses its antiseizure efficacy and conversely exacerbates epileptiform activity during this stage of SE-like activity. Interestingly, a low concentration of the barbiturate phenobarbital had a similar exacerbating effect on SE-like activity, whilst a high concentration of phenobarbital was effective at reducing or preventing epileptiform discharges. We then show that the persistent SE-like activity is associated with a reduction in GABAA receptor conductance and Cl- extrusion capability. We explored the effect on intraneuronal Cl- using both gramicidin, perforated-patch clamp recordings and Cl- imaging. This showed that during SE-like activity, reduced Cl- extrusion capacity was further exacerbated by activity-dependent Cl- loading, resulting in a persistently high intraneuronal Cl-. Consistent with these results, we found that optogenetic stimulation of GABAergic interneurons in the SE-like state, actually enhanced epileptiform activity in a GABAAR dependent manner. Together our findings describe a novel potential mechanism underlying benzodiazepine-resistant SE, with relevance to how this life-threatening condition should be managed in the clinic.

scholarly journals Energy coupling to the transport of inorganic phosphate in Escherichia coli K12

1979 ◽  
Vol 178 (1) ◽  
pp. 133-137 ◽  
Author(s):  
H Rosenberg ◽  
R G Gerdes ◽  
F M Harold
Keyword(s):  
Escherichia Coli ◽  
Energy Source ◽  
Inorganic Phosphate ◽  
Energy Coupling ◽  
Phosphate Transport ◽  
Proton Motive Force ◽  
High Concentration ◽  
Concentration Gradients ◽  
Transport Of Inorganic Phosphate ◽  
Pst System

The nature of the energy source for phosphate transport was studied in strains of Escherichia coli in which either one of the two major systems (PIT, PST) for phosphate transport was present. In the PIT system, phosphate transport is coupled to the proton-motive force. The energy source for the PST system appears to be phosphate-bond energy, as has been found in other systems involving binding proteins. High concentration gradients of phosphate (between 100 and 500) are established by both systems.

FACTORS AFFECTING THE INCORPORATION OF RADIOACTIVE PHOSPHATE INTO THE PHOSPHOLIPIDS OF SLICES OF CAT BRAIN

1954 ◽  
Vol 32 (1) ◽  
pp. 50-59 ◽  
Author(s):  
K. P. Strickland
Keyword(s):  
Oxygen Consumption ◽  
Inorganic Phosphate ◽  
Brain Slices ◽  
Phospholipid Fraction ◽  
Metabolic Inhibitors ◽  
Factors Affecting ◽  
Wide Range ◽  
Cat Brain

Slices of cat brain respiring in a Krebs–Ringer bicarbonate medium were found to incorporate radioactive inorganic phosphate (P32) into the phospholipid fraction. The addition of glucose or mannose increased the incorporation of P32 into the phospholipids. Fructose caused a small increase, whereas galactose was without effect. Pyruvate and lactate increased the incorporation of P32 into the phospholipids. Succinate, L (+)-glutamate, D (−)-glutamate, α keto-glutarate, citrate, and L-malate failed to support the incorporation.Anaerobic conditions and homogenization of the tissue prevented the in vitro incorporation of P32 into the phospholipids of cat brain. A wide range of metabolic inhibitors (cyanide, azide, malononitrile, chloretone, nembutal, iodoacetate, and fluoride), in concentrations that inhibit the oxygen consumption of brain slices, inhibited the incorporation. The incorporation was also inhibited by 2,4-dinitrophenol in concentrations that do not decrease the oxygen consumption of brain slices.These findings indicated that the incorporation of P32 into the phospholipids of slices of cat brain is a metabolic phenomenon and is dependent upon the maintenance of an adequate phosphorylating mechanism within the slice.

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