bluuebunny/crossref_metadata_2025_split huggingface dataset:
ANALYSE ELECTROPHORETIQUE COMPAREE DES PROTEINES CEREBRALES TOTALES, SOLUBLES ET PARTICULAIRES, CHEZ CINQ SOUCHES DE SOURIS
Authors: Bobillier P. , Seguin S. , Renaud B. , Valatx J. L. 
Published: October 2006

Résumé

Nous avons compareé chez cinq souches de souris adultes Quaking (Qk), C57BL/6, CBA, DBA/2 et CS7BR la distribution des protéines cérébrales totales (solubles en milieu salin ou détergent, acides à pH 8,9 ou basiques à pH 4,3) de fractions subcellulaires obtenues par séparation électrophorétique sur gel de polyacrylamide en gradient discontinu de pH.
Chez le mutant Qk compareéà son témoin des différences quantitatives significatives et une mobilityéélectrophorétique anormale sont mises en évidence respectivement au niveau des protéines acides à poids moléulaire élevé de la myéline et au niveau des protéines solubles à poids moléulaire faible de la myéline et des synaptosomes. Entre Qk et témoin, aucune différence n'est déelable parmi les protéines des fractions nucléires, mitochond‐riales ou microsomales.
Les incubations in vivo d'acides aminés tritiés réalisées chez la souris Qk révélent une augmentation de I'incorporation du préurseur dans deux fractions des protéines solubles, acides de la fraction cytoplasmique non particulaire.
Les profils électrophorétiques des protéines cérébrales étudiéés chez trois autres souches consanguines (CBA, DBA/2 et C57BR) sont identiques à I'exception de DBA/2 dont les protéines solubles et acides du surnageant cytoplasmique sont caractérisées par deux bandes mineures additionnelles. Les anomalies protéiques observées sont discutées en fonction des troubles de la myélinisation du systéme nerveux central et de la possibilityé d'une induction cellulaire multienzymatique d'origine génétique.
RATES OF CEREBRAL GLUCOSE UTILIZATION IN RATS ANAESTHETIZED WITH PHENOBARBITONE
Authors: Strang R. H. C. , Bachelard H. S. 
Published: October 2006

Abstract—

Intraperitoneal injection of phenobarbitone (250 mg/kg body wt.) into rats caused increased brain concentrations of glucose (100 per cent), glucose 6‐phosphate (16 per cent) and ATP (12 per cent) and decreased concentrations of lactate (33 per cent) and ADP (15 per cent). A 31 per cent decrease in glutamate content was not statistically significant. No significant change occurred in the cerebral contents of glycogen or creatine phosphate.
The rates of increase in the brain of specific activities, in the first few minutes after systemic injection of [U‐14C]glucose, of glucose, lactate, glutamate and glycogen were all halved by phenobarbitone. Calculated flux rates of 14C from glucose into metabolic intermediates and from lactate to glutamate were also decreased by 27–47 per cent; the effects on rate constants showed inconsistencies. The rate constants for conversion of glucose to lactate and to glutamate were decreased by 60–70 per cent, but that from lactate to glutamate was virtually unchanged. The rate constant for the flux from glucose to glycogen was reduced by 39 per cent, but the accumulation of glucose meant that the actual flux into glycogen increased by 20 per cent.
The results are interpreted in terms of an effect of the barbiturate not only on glucose transport, but also at an enzymic stage in glycolysis, possibly hexokinase or phosphofructokinase.
ADENOSYLMETHIONINE DECARBOXYLASE IN DEVELOPING RAT BRAIN
Authors: Schmidt G. L. , Cantoni G. L. 
Published: October 2006

AbstractAdenosylmethionine decarboxylase from rat brain has been found to be similar to the same enzyme isolated from other rat tissues in regard to kinetic parameters, pH optimum, putrescine requirement, and subcellular location. Evidence is presented that pyridoxal phosphate is not the functional cofactor in enzymatic decarboxylation by the rat brain preparation. The capacity for spermidine synthesis in developing rat brain was determined by measurement of the activity of adenosylmethionine decarboxylase. The activity increased dramatically after 10 days of postnatal age. This increase occurred after the period of maximum nucleic acid synthesis, an observation which suggests that spermidine may have a role in the functional development of the brain.
ON THE MECHANISM OF TAURINE TRANSPORT AT BRAIN CELL MEMBRANES
Authors: Lähdesmäkt P. , Oja S. S. 
Published: October 2006

AbstractOne non‐saturable and two saturable transport systems were demonstrated for taurine in rat brain slices. One of the saturable systems, designated β, is characterized by a high asnity for taurine and a low transport capacity, while the other, designated ω, by a low affinity and a high transport capacity. 2,4‐Dinitrophenol inhibited the saturable transport of taurine non‐competitively, while hypotaurine. β‐alanine, γ‐aminobutyric acid, N‐methyl‐taurine and L‐cysteic acid inhibited transport competitively. It is thus inferred that the hypothetical carrier sites of taurine at cell membrane recognize to an equal degree strongly ionized electropositive and electronegative ends of an acceptable molecule separated by two or three carbon atoms. Two is the minimal and also the optimal carbon chain length in an acceptable molecule.
THE RELATIONSHIP BETWEEN DNA SYNTHESIS AND NUCLEAR PROTEINS IN THE CEREBRUM AND CEREBELLUM OF 8‐DAY‐OLD RATS
Authors: Burdman J. A. , Szijan I. , Franzoni L. , Argiz C. A. Garcia 
Published: October 2006

AbstractIn‐8‐day‐old rats the higher rate of DNA replication in cerebellum than in cerebrum is accompanied by an enhanced synthesis of nuclear proteins. The greatest difference between the incorporation of tritiated leucine into proteins of cerebral and cerebellar cell nuclei occurs in the acid‐soluble deoxyribonucleoproteins. However, the specific radioactivity of the acidic deoxyribonucleoproteins is similar in both tissues. The relative content of these proteins and the activity of the RNA polymerase is higher in cerebrum than in cerebellum. The results suggest that in the cerebrum of young rats these proteins are mainly concerned with the regulation of RNA synthesis.
BIOGENIC AMINES AND THEIR METABOLITES AS SUBSTRATES FOR PHENOL SULPHOTRANSFERASE (EC 2.8.2.1) OF BRAIN AND LIVER
Authors: Meek J. L. , Neff N. H. 
Published: October 2006

AbstractPhenol sulphotransferase activity in homogenates of rat liver and brain was determined spectrophotometrically. Rat liver had about 100‐fold more phenol sulphotransferase activity than brain; however, both tissues showed about the same spectrum of activity towards the phenolic compounds tested. Dopamine and its acidic and neutral metabolites and the neutral metabolites of norepinephrine were the compounds most readily sulphury‐lated in vitro. They were also the compounds most readily sulphurylated in vivo when they were injected intraventricularly together with labelled Na2SO4. When labelled Na2SO4 was injected alone, we detected conjugation of endogenous phenols. One of the compounds formed was identified by its chromatographic characteristics as 3‐methoxy‐4‐hydroxy‐phenylethyleneglycol sulphate. We detected other conjugates which appeared to be the sulphate esters of 3,4‐dihydroxyphenylethyleneglycol; 3,4‐dihydroxyphenylacetic acid; and homovanillic acid. In brain, sulphate conjugation may be a major route of metabolism for many of the phenolic compounds related to the biogenic amines and possibly for phenolic drugs which enter the brain.
CATECHOLAMINES IN FETAL AND NEWBORN RAT BRAIN
Authors: Coyle J. T. , Henry D. 
Published: October 2006

AbstractThe levels of dopamine and norepinephrine were determined in the brains of fetal and newborn rats by means of a sensitive, radiometric‐enzymatic assay. Catecholamines were converted to their 3‐O‐methylated derivatives in the presence of catechol‐O‐methyl transferase (EC 2.1.1.1) and [3 H‐methyl]S‐adenosylmethionine; and the [3H]‐derivatives were isolated by selective extraction. The assay had a sensitivity for dopamine and norepinephrine of 100 picograms and was linear to at least 30 nanograms of catecholamines. Both amines were present at 15 days of gestation and increased 15‐fold in content during the last week of gestation. The regional distribution of these neurotransmitters in the brain of the newborn rat correlated with the distribution of their biosynthetic enzymes. An investigation of the effects of reserpine, pheniprazine, α‐methyl‐para‐tyrosine, diethyldithiocarbamate and l ‐DOPA on the levels of dopamine and norepinephrine in the brains of the 18‐day gestational fetus indicated that the levels of these neurotransmitters are under controls similar to those known to occur in the brain of the adult rat.
THE DISTRIBUTION OF SEVERAL AMINO ACIDS IN SPECIFIC GANGLIA AND NERVE BUNDLES OF THE LOBSTER1
Authors: Aprison M. H. , Mcbride W. J. , Freeman A. R. 
Published: October 2006

AbstractUsing the technique of measuring DNP‐amino acid methyl esters by gas‐liquid chromatography, the distribution of alanine, proline, glycine, GABA, glutamate and aspartate was determined in individual ganglia and the associated nerve bundles between these ganglia after isolation from the nervous system of the lobster, Homarus americanus. The brain or supraesophageal ganglion (27.2 mg) and the next 5 thoracic ganglia (varying from 24 to 10 mg in a rostral–caudal direction) as well as the nerve bundles connecting these ganglia were used. GABA and aspartate values varied the most among the individual ganglia; highest values were found in the second and third thoracic ganglia. The levels of alanine, proline, glycine and glutamate varied very little from ganglion to ganglion; however, the values for these amino acids did exhibit some variability among the individual connectives. The highest value for each was in the nerve bundle between the first and second thoracic ganglion. Glycine was present at the highest level of any of the amino acids whereas GABA was at the lowest level in the individual structures assayed.
A SENSITIVE SPECIFIC ENZYMATIC‐FLUOROMETRIC ASSAY FOR HOMOCARNOSINE1
Authors: Young Anne B. , Snyder S. H. 
Published: October 2006

AbstractWe have developed a sensitive and specific assay for homocarnosine in tissues. Homocarnosine is separated from GABA by ion exchange chromatography. After hydrolysis of homocarnosine with swine kidney carnosinase, the evolved GABA is measured by an enzymatic‐fluorometric procedure. As little as 0.1 nmol of tissue homocarnosine can be detected by this procedure. Homoanserine, which would be detected by this assay, can be separated from homocarnosine by thin layer chromatography. No homoanserine could be detected in any tissues examined. There are marked regional variations in levels of homocarnosine in guinea‐pig brain that do not correspond to regional differences in GABA levels.
NOREPINEPHRINE METABOLISM IN THE CENTRAL NERVOUS SYSTEM OF MAN: STUDIES USING 3‐METHOXY‐4‐HYDROXYPHENYLETHYLENE GLYCOL LEVELS IN CEREBROSPINAL FLUID
Authors: Chase T. N. , Gordon Edna K. , Ng L. K. Y. 
Published: October 2006

Abstract—Levels of 3‐methoxy‐4‐hydroxyphenylethylene glycol (MHPG), a major metabolite of norepinephrine, were measured in human CSF by gas‐liquid chromatography. MHPG concentrations were similar in both ventricular and lumbar CSF samples; about 30 per cent of the MHPG from either source occurred as the sulphate conjugate. There was relatively little entry of intravenously infused [14C]MHPG into lumbar spinal fluid. Both α‐methylparatyrosine, an inhibitor of tyrosine hydroxylase, and fusaric acid, an inhibitor of dopamine‐β‐hydroxylase, significantly diminished MHPG values. On the other hand, doses of l‐DOPA or probenecid, sufficient to substantially elevate CSF levels of the dopamine metabolite, homovanillic acid, failed to alter the spinal fluid content of MHPG. CSF concentrations of MHPG in patients with Parkinson's disease or the other central nervous system disorders studied did not differ significantly from control levels. The results suggest that MHPG values in CSF may provide an index to norepinephrine metabolism in the central nervous system of man.
REGIONAL DISTRIBUTION OF GLUTAMIC ACID DECARBOXYLASE IN THE DEVELOPING BRAIN OF THE PYRIDOXINE‐DEFICIENT RAT
Authors: Bayoumi R. A. , Smith W. R. D. 
Published: October 2006

Abstract—Glutamic acid decarboxylase was determined in seven brain regions: hypo‐thalamus; midbrain; thalamus; corpus striatum; cerebral cortex‐hippocampus; medulla‐pons; and cerebellum, of suckling rats subjected to Vitamin B6 deficiency for 2 weeks from birth; of adult rats subjected to the deficiency for 5 weeks and of their respective controls. Large regional variations in the enzyme activity were found in brains of both adult and suckling control rats. The activity of the enzyme (assayed without pyridoxal phosphate) and its saturation with endogenous cofactor were markedly reduced in all brain regions of both suckling and adult pyridoxine‐deficient rats. The apoenzyme (activity assayed with pyridoxal phosphate), in adult rat brain, showed no change with the deficiency in all regions except in the cerebellum where it increased slightly. In pyridoxine‐deficient suckling rat brain, the apoenzyme increased substantially in all regions suggesting a process of enzyme induction. The increase in apoenzyme varied from region to region.
REGIONAL AND SUBCELLULAR DISTRIBUTION OF CHOLINE ACETYLTRANSFERASE IN THE BRAIN OF RATS1
Authors: Wajda I. J. , Manigault I. , Hudick J. P. , Lajtha A. 
Published: October 2006

Abstract—Homogenates of corpus striatum, cerebral cortex and hypothalamus excised from rat brain were fractionated on discontinuous Ficoll and sucrose density gradients, and the distribution of choline acetyltransferase (ChAc) in the mitochondrial and synaptosomal fractions was determined. In the hypothalamic and cortical regions the fractions enriched in synaptosomes showed much higher activity of ChAc than those containing mainly mitochondria. On the other hand, the corpus striatum showed an equal distribution of ChAc activity in those two fractions. The localization of ChAc was also studied in the postnuclear supernatants obtained from three brain regions, using continuous sucrose density gradients. The distribution of ChAc was compared to that of monoamine oxidase (MAO), potassium and protein. When the pellets obtained from the fractions collected from the gradient were suspended in sucrose, the peak of ChAc activity was close to that of MAO in all three brain regions. When 0.1 mm EDTA +1% butanol was used in order to liberate the occluded form of ChAc, the maximum liberation occurred in lighter fractions, resulting in a shift of the activity peak toward the top of the gradient. This was found with fractions from hypothalamic and cortical regions. In the striatum, the liberated ChAc remained in the same fractions as the occluded enzyme. The results indicate that ChAc is liberated only in those fractions where it is present in synaptosomes. In agreement with the results on the discontinuous gradients this occurs in particles of lower density than mitochondria in cortex and hypo‐thalamus, but in particles of similar density to mitochondria in the corpus striatum, indicating regional differences in the distribution of ChAc in the brain. K+ containing particles centrifuged in less dense fractions than those containing ChAc, indicating that synaptosomes are heterogeneous with respect to these two marker substances.
DDT EFFECT ON 32P INCORPORATION FROM γ‐LABELLED ATP INTO PROTEINS FROM LOBSTER NERVE
Authors: Doherty J. D. , Matsumura F. 
Published: October 2006

AbstractThe insecticide DDT (1,1,1 trichloro‐2,2‐bis‐(p‐chlorophenyl) ethane) was found to affect the amount of 32P from [γ‐32P] ATP incorporated into proteins derived from lobster peripheral nerves in a variety of ways depending upon the relative concentrations of ATP, Na+, K+, Mg2+, and Ca2+. When a high concentration of ATP (2.5 ± 10−5m) was used DDT (10−5m) inhibited the incorporation and reversed the increased incorporation caused by ouabain. At low concentration of ATP (8.6 ± 10 −8m), DDT inhibited the incorporation when the buffer contained Mg2+ and Na+ or K+ alone, but when the buffer contained Mg2+ and both Na+ and K+ together, DDT consistently caused an increased amount of 32P to be incorporated. The ability of DDT to cause increases in incorporation of 32P into the lobster nerve proteins was found to parallel many of the properties that this compound shows when allowed to poison crustacean nerves. For example: the effect was negatively temperature dependent, Ca2+ lowered the incorporation in the presence of DDT, and DDT consistently caused greater amounts of 32P to be incorporated than its less potent analog DDE (1,1‐dichloro‐2,2‐bis‐(p‐chlorophenyl)ethylene). The proteins that were affected by DDT were microsomal in nature and could be centrifuged from supernatant by recentrifuging at 149,000 g. The possibility that this system may be the actual target through which DDT causes its characteristic interferences of the ionic conductance changes associated with the action potential are discussed.
THE UPTAKE OF GABA INTO RAT SPINAL ROOTS
Authors: Davies J. , Johnston G. A. R. 
Published: October 2006

Abstract—Dorsal and ventral roots, dissected from rats anaesthetized with sodium pentobarbitone, accumulated three to four times more GABA than l‐glutamate, 1‐aspartate or glycine during 30 min incubation at 37°C. GABA was taken up into spinal roots by a structurally specific, sodium‐dependent process with an apparent Km of approx. 3 × 10−5m. This uptake process appears to be very similar to that described in rat brain, spinal cord and dorsal root ganglia.
TIME‐DEPENDENT CHANGES IN BRAIN BIOGENIC AMINE DYNAMICS FOLLOWING CASTRATION IN MALE RATS1
Authors: Bernard B. K. , Paolino R. M. 
Published: October 2006

Abstract—Alterations in whole‐brain and hypothalamic levels of serotonin (5‐HT), 5‐hydroxyindoleacetic acid (5‐HIAA), norepinephrine (NE), dopamine (DA) as well as the turnover rates of NE and DA of adult male rats were analysed fluorometrically at either 3 weeks or 6 weeks following castration. Significant increases were observed in whole‐brain (minus hypothalamus) 5‐HIAA levels and hypothalamic DA levels, fractional rate constants and utilization rates at the 3 but not the 6 week intervals. Elevated levels of 5‐HT were observed at both time intervals while an increase in whole‐brain DA was seen only at the 6 week interval. Whole brain NE turnover rates of castrated animals did not differ significantly from those of sham‐castrate control animals at either test interval. However, a tendency toward increased hypothalamic NE turnover rates was seen in the castrated animals. These biochemical changes resulted in decreased NE/5‐HT and DA/5‐HT ratios for the castrate rats as compared to controls.The results are discussed in relation to emotional and aggressive behavior and are interpreted as being consistent with the hypothesis purporting an inhibitory role for 5‐HT and excitatory role for NE and DA in sex‐specific behavior patterns including aggression.
AXONAL TRANSPORT OF PHENYLETHANOLAMINE‐N‐METHYLTRANSFERASE IN TOAD SCIATIC NERVE
Authors: Wooten G. F. , Saavedra J. M. 
Published: October 2006

Abstract—The presence of phenylethanolamine‐N‐methyltransferase (EC 2.1.1.‐) and dopamine‐β‐hydroxylase (EC 1.14.2.1) activities was demonstrated in the sciatic nerve of the toad, Bufo marinus. The rates of accumulation of phenylethanolamine‐N‐methyltransferase (PNMT) and dopamine‐β‐hydroxylase (DBH) proximal to a ligation of the sciatic nerve were studied. DBH accumulated proximal to the ligation at a more than 10‐fold faster rate than PNMT. By measuring the rate of loss of enzyme activity distal to a ligation, an estimate of per cent clearance of each enzyme was made. Based on the per cent of enzyme activity free to move, the absolute transport rates for each enzyme were estimated to be: PNMT, 3.6 mm/24 h; DBH, 102 mm/24 h. PNMT activity (89 per cent) was recovered in the soluble fraction of sciatic nerve homogenates with no change occurring in the subcellular distribution of the enzyme proximal to ligations. In contrast, 43 per cent of DBH activity was found in the soluble fraction of sciatic nerve homogenates; but a disproportionate increase in paniculate DBH activity was found proximal to sciatic nerve ligations. Reduction of toad body temperature to 4°C resulted in a complete but totally reversible block of the axonal transport of both PNMT and DBH.
EFFECT OF LIGHT ON GANGLIOSIDES FROM CALF RETINA AND PHOTORECEPTORS
Authors: Dreyfus H. , Urban P. F. , Bosch P. , Edel‐Harth S. , Rebel G. , Mandel P. 
Published: October 2006

Abstract—The gangliosides of the whole calf retina and the rod outer segments have been analysed. This has been done in two functional states: before and after stimulation by light. After exposure to light no statistically significant change in the gangliosides of the whole retina was observed, but a 40 per cent increase in concentration was found in the rod outer segments. This difference was apparent only when using the same batch of rod outer segments. The major ganglioside in the whole calf retina is GD3 which accounts for 46 per cent of the total. Three other gangliosides GD1a, GD1b and GT1 are quantitatively important, each being between 12 and 16 per cent. GQ1, GM1, and GM3 are minor constituents. In contrast to the chicken retina, GM2 was not detected. The ganglioside N‐acetylneuraminic acid of the rod outer segments accounts for only 1 per cent of the gangliosides of the whole retina. The composition of the gangliosides in the rod outer segments is essentially the same as that of the whole retina. No difference in the relative proportion of the gangliosides of either the rod outer segments or the whole retina was observed after exposure to light.
OCCURRENCE AND LOCALIZATION OF BRAIN PHENOLSULPHOTRANSFERASE
Authors: Foldes A. , Meek J. L. 
Published: October 2006

Abstract—Rat brain contains the enzyme which forms sulphate conjugates of phenols, phenolsulphotransferase (EC 2.8.2.1), but the physiological role of the enzyme is unclear. The enzyme is unevenly distributed in rat brain, with the activity 13 times higher in the hypothalamus than in the cerebellum. Phenolsulphotransferase does not seem to be primarily located in glial cells. Cultured cells (type C6 astrocytoma) derived from rat glia had less than 1 per cent of the phenolsulphotransferase activity of whole rat brain. Sulphate conjugation of neutral compounds may be important in their removal from brain. The pineal and pituitary glands, areas outside the blood‐brain barrier had very low phenolsulphotransferase activity. The activity of the enzyme in brain varied widely among different species: rabbit and rat had much higher levels of activity than mouse or frog; the activity in human brain was intermediate. Phenolsulphotransferase also occurred in other organs, including liver, heart, testes, lung, spleen, salivary glands, and intact or decentralized superior cervical ganglion. There was no correlation of enzyme activity with adrenergic or cholinergic innervation, or with the known roles of various tissues in drug metabolism or detoxification. The enzyme activity does not seem to be under neuronal control since ganglionectomy did not affect the phenolsulphotransferase activity of salivary glands. The precise localization of phenolsulphotransferase remains to be established, as well as the physiological importance of sulphate conjugation of phenols in brain and other organs.