bluuebunny/crossref_metadata_2025_split huggingface dataset:
INHIBITION OF NOREPINEPHRINE RE‐UPTAKE BY ANGIOTENSIN IN BRAIN1
Authors: Palaic D. , Khairallah P. A. 
Published: October 2006

Abstract—A method for perfusion of rat brain ventricles accompanied by electrical stimulation of right vagus nerve was used in the study of the re‐uptake mechanism of norepinephrine in rat brain. Tritiated norepinephrine was injected into the left lateral brain ventricle. After a 1‐hr equilibration period, the brain was perfused, and effluent was collected and assayed for norepinephrine, normetanephrine and acid metabolites by means of column chromatography and liquid scintillation counting. Electrical stimulation of central end of right vagus nerve produced a significant release of norepinephrine and decrease of acid metabolites; this indicates a shift of catecholamines to extracellular sites. Angiotensin (200 ng/min) added to the perfusion fluid potentiated the effect of nerve stimulation. Cocaine, desmethylimipramine and phenoxybenzamine greatly reduced the release of norepinephrine from brain tissue. None on these drugs potentiated the effect of angiotensin. It is concluded that angiotensin prevents re‐uptake of norepinephrine released by nerve stimulation. As a naturally occurring, physiologically active peptide, angiotensin seems to be highly specific in modulation of adrenergie neurotransmission, allowing increased extraneuronal accumulation of neurotransmitter.
STEROLS WITH 29, 28 AND 27 CARBON ATOMS METABOLICALLY RELATED TO CHOLESTEROL, OCCURRING IN DEVELOPING AND MATURE BRAIN1
Authors: Weiss J. F. , Galli G. , Paoletti E. Grossi 
Published: October 2006

Abstract—Brain sterols from chick embryos (11 and 18 days of incubation) and mature rats, previously injected with [2‐14C]mevalonate, were analysed.Acetate derivatives of the sterols were chromatographed on Silica Gel:Celite:AgNO3 columns. Sterol fractions were assayed for radioactivity and the amounts determined by gas chromatography. Sterol structures were elucidated by gas chromatography‐mass spectrometry. The method used allowed the identification of some sterols representing no more than 0‐01 per cent of the total mixture.The following brain sterols were identified: cholesterol, cholestanol, cholest‐5,24‐dien‐3β‐ol (desmosterol); 4,4′‐dimethyl‐cholest‐8‐en‐3β‐ol, 4α‐methyl‐cholest‐8‐en‐3β‐ol, cholest‐8‐en‐3β‐ol, 4,4′‐dimethyl‐choIest‐8,24‐dien‐3β‐ol, 4α‐methyl‐cholest‐8,24‐dien‐3β‐ol, cholest‐8,24‐dien‐3β‐ol and cholest‐7,24‐dien‐3β‐ol. Small amounts of other sterols including polyhydroxy sterols, were also detected. There were no qualitative differences in the sterols detected in developing and mature brain. In the developing chick brain, cholesterol represented approximately 90 per cent of the total sterols. In the mature rat brain, cholesterol accounted for 98 per cent of the sterols.The adult rat brain, as well as the embryonic chick brain, demonstrated the capacity to incorporate mevalonate into cholesterol precursors and cholestanol. The sterols retaining the double bond in the lateral chain, that is, those of the Δ8,24 series with 29, 28 and 27 carbon atoms and desmosterol, were highly labelled compared with the other identified intermediates. The possibility, supported by our data, that a preferential biosynthetic route for cholesterol exists in brain, is discussed.
ELEVATED PLASMA PHENYLALANINE CONCENTRATION AND LYSINE INCORPORATION INTO RIBOSOMAL PROTEIN OF DEVELOPING BRAIN
Authors: Swaiman K. F. , Hosfield W. B. , Lemieux B. 
Published: October 2006

Abstract—Hyperphenylalaninemia was induced in 7‐day‐old rabbits over a 6‐hr period by intraperitoneal injection of phenylalanine. l‐[U‐14C]Lysine was injected intraperitoneally into these rabbits and into a control group. The rate of incorporation of l‐[U‐14C]lysme into brain ribosomal protein was decreased during a 5‐hr period in the presence of elevated plasma phenylalanine concentrations. Lysine transport from the peritoneum to the plasma was unaffected by the high plasma phenylalanine concentrations.
ADRENAL CATECHOLAMINES AND RELATED CHANGES DURING DIFFERENT PHASES OF MORPHINE ADMINISTRATION—A HISTOCHEMICAL STUDY
Authors: Ray A. K. , Mukherji M. , Ghosh J. J. 
Published: October 2006

Abstract— (1) Acute morphine treatment of rats reduced the total catecholamine content as well as the noradrenaline content of the adrenal gland. This was accompanied by increased ATPase activity and increased calcium content of the medullary cells.(2) After chronic morphine treatment, the total catecholamine content remained more or less unaltered, but the noradrenaline content was markedly increased together with the noradrenaline‐containing areas, in comparison with what was observed in control animals. The ATPase activity of the medullary cells was found to be diminished along with the decreased calcium content.(3) In nalorphine‐induced abstinence, a decrease in total catecholamine content together with a reduction of noradrenaline content and of noradrenaline‐containing areas were observed. ATPase activity was also found to be increased with increased calcium content.
ESTERASES OF DEVELOPING HUMAN BRAIN*
Authors: Barron K. D. , Bernsohn J. 
Published: October 2006

Abstract The free and bound nonspecific esterases occurring in, respectively, the saline and triton X‐100 extracts of adult and developing human brain were studied by starch gel electrophoresis (zymograms). Zymograms of the free esterase fraction visualized with NA as substrate were qualitatively similar at 5‐12 days of age to the electrophoretic patterns observed in adult material. In both adult and developing brain, zymograms of bound esterase resembled those of the free enzyme, the major difference being the presence in the former of a slow, broad, anodic zone of diethyl‐p‐nitrophenyl phosphate‐inhibited enzyme.Esterases characteristic of adult white matter and having preferential affinity for alpha‐naphthylpropionate, alpha‐naphthyl butyrate and alpha‐naphthyl valerate were not identified in infant brain until about 4 months postnatal age.A far‐moving, anodic enzyme was distinctly evident in zymograms of brains of less than 1 month of age. This enzyme hydrolysed NP, NB, and NV more actively than alpha‐naphthyl acetate. It was present in the adult brain but, in contrast to the infant, was no longer electrophoretically‐separable from another enzyme which had greater affinity for NA and had previously been designated the A10 band.Quantitative assays demonstrated that the bound esterase increased in cerebral and cerebellar cortex during development. In contrast, the proportion of free to bound esterase showed little change in white matter.Acetylcholinesterase and butyrylcholinesterase zymograms became identical to adult patterns from 1 to 4 months of age.Thiolacetic acid esterase was present at 38 weeks gestation.Some functional and anatomical correlations were attempted in explanation of the biochemical observations.
ISOLATION AND DETERMINATION OF NON‐DIFFUSIBLE SIALOFUCOHEXOSAMINOGLYCANS DERIVED FROM BRAIN GLYCOPROTEINS AND THEIR ANATOMICAL DISTRIBUTION IN BOVINE BRAIN
Authors: Brunngraber Eric G. , Brown Barbara D. , Aguilar Virginia 
Published: October 2006

Abstract— Glycoproteins in brain tissue were assayed by determining the amount of N‐acetylneuraminic acid (NANA), hexosamine, hexose, and fucose present in glycopeptides released by the proteolytic action of papain on the defatted protein residue that remains after treatment of the sample with chloroform‐methanol (2:1 and 1:2, v/v). Diffusible and non‐diffusible glycopeptides (sialofucohexosaminoglycans) were released by proteolysis. The procedure demonstrated that successive treatment of brain tissue with chloroform‐methanol (2:1, v/v) and chloroform‐methanol (1:2, v/v) removed all of the gangliosides present in the tissue.A 1 hr autolysis of rat brain tissue had no effect on the amount of glycopeptides recovered from the tissue. The carbohydrate composition of the non‐diffusible sialofucohexosaminoglycans was also unaffected.Areas of the brain that are enriched in neuronal cell bodies contained a higher concentration of gangliosides and glycoproteins than areas that consist largely of myelinated fibre tracts. On the other hand, there was a greater concentration of glycoprotein relative to that of gangliosides in areas that consist predominately of myelinated fibre tracts and glia than in areas enriched in neuronal cell bodies. The concentration of non‐diffusible sialofucohexosaminoglycans in whole bovine brain was less than that in whole rat brain. The non‐diffusible sialofucohexosaminoglycans from whole bovine brain contained less fucose and NANA per mole of hexosamine and hexose than non‐diffusible sialofucohexosaminoglycans isolated from whole rat brain. The non‐diffusible sialofucohexosaminoglycans isolated from bovine cerebral white matter were lower in fucose and NANA content per mole of hexose and hexosamine than those isolated from other brain areas. It is suggested that the fucose and NANA content of the non‐diffusible sialofucohexosaminoglycans associated with myelinated axons and (or) glia is less than that of the non‐diffusible sialofucohexosaminoglycans associated with the nerve cell body.
TRANSPORT OF 14C INCORPORATED PROTEIN IN THE CORTICOSPINAL TRACT OF THE RAT BRAIN
Authors: Foulkes J. A. , Robinson N. 
Published: October 2006

Abstract— The origin of fibres of a corticospinal pathway in rat brain was located by cortical ablation and Marchi staining and also by electrical stimulation of the motor cortex.Enzyme changes investigated histochemically over 0–14 days post‐injection of 5 μ10.15 m NaCl into the neocortex indicated that very little apparent disturbance of nerve cell metabolism beyond a narrow band adjacent to the path of the microneedle within the cortex had occurred. [14 C]Leucine as a precursor of protein synthesis was used to study incorporation of the amino acid into protein. At the site of injection the maximum level of labelled protein was recorded at 30 min post‐injection, the level decreasing to less than 2 per cent of this at 6 hr.The subsequent axonal flow of labelled protein along the corticospinal pathway was investigated during the period 15 min to 21 days post‐injection. Within 24 hr increasing amounts of labelled proteins were measured caudally, but not more than 6 per cent had migrated beyond 5 mm from the site of injection. At 3 days this percentage had increased to 14.6 per cent, the labelled proteins being distributed in progressively decreasing amounts to a further 13 mm caudal. Very little change from this position was seen during the following 18 days.
THE INFLUENCE OF EXCESS METHIONINE ON THE FREE AMINO ACIDS OF BRAIN AND LIVER OF THE WEANLING RAT*
Authors: Daniel R. G. , Waisman H. A. 
Published: October 2006

Abstract— —High circulating levels of l‐methionine produced by inclusion in the diet or parenteral injection of the amino acid caused alterations in the free amino acid pattern of liver and brain tissues. Acute effects following l‐methionine injection were more pronounced than those following long term feeding where adaptation played a role. The net effect following parenteral injection was to increase the total free amino acids of liver while decreasing those of brain.Individually, hepatic levels of aspartic acid, threonine, serine, glutamine, glutamic acid, glycine, and alanine were depressed while levels of taurine, cystathionine, methionine, lysine, and ornithine were markedly elevated. Brain levels of aspartic acid, threonine, serine, glutamic acid, glycine, alanine, and γ‐aminobutyric acid were markedly depressed and increased levels of cystathionine, methionine, lysine, and glutamine were observed.A generalized aminoaciduria occurred shortly after excessive methionine intake.Disruption of the free amino acid pools was of two kinds. The first depended on the continued presence of excess l‐methionine, the second did not.
EFFECTS OF DIFFERENT SUPPLEMENTS TO LOW PROTEIN AND POOR QUALITY PROTEIN DIETS ON PERFORMANCE AND BRAIN ENZYMES IN THE ALBINO RAT1
Authors: Rajalakshmi R. , Pillai K. R. , Ramakrishnan C. V. 
Published: October 2006

Abstract—Groups of albino rats were fed low and high protein diets and the former group was fed with different supplements. The supplements used were niacin, pyridoxine and glutamic acid. A low protein diet was found to decrease the activities of l‐glutamate‐NAD‐oxidoreductase and l‐glutamate‐1‐carboxy‐lyase in the cerebrum; this confirmed the results of previous work in this laboratory. Addition of glutamic acid to a low protein diet was found to reverse the effects of a low protein diet to some extent.Groups of animals were fed kodri (Paspalum scorbiculatum), a millet deficient in lysine, with or without lysine itself or foodstuffs rich in it, e.g. moth bean (Phaseolus aconitifolius Jacq.), peas (Pisum sativuni) and skim milk powder. When combined, the groups fed on the lysine or lysine‐source supplemented diets were found to perform better in a water maze on the basis of the relative ease with which they could reverse a previous learned pattern. They also had higher activities of l‐glutamate‐NAD‐oxidoreductase and l‐glutamate‐1‐carboxy‐lyase than groups with no lysine or lysine source added. There was no significant difference between the groups receiving the different lysine supplements.
COMPARISON OF THE BEHAVIOUR OF A SOLUBLE AND A MEMBRANE‐BOUND ENZYME IN TRANSECTED PERIPHERAL NERVES
Authors: Skangiel‐Kramska Jolanta , Niemierko Stella , Lubińska Liliana 
Published: October 2006

Abstract—Phosphoglucoisomerase (PGI), a soluble enzyme, and AChE, a membrane‐bound enzyme were studied in transected peroneal nerves of dog and in isolated segments of these nerves. Although activities of both enzymes increased at the ends of transected nerves, marked differences in their behaviour were observed. The increment in AChE activity was much sharper than that of PGI and continued to grow with time whereas the increase in PGI developed fully within the initial hours after transection and did not change thereafter.In an isolated nerve segment AChE accumulated at both ends with a concomitant decrease in the middle part, whereas changes in PGI activity appeared only in the terminal parts, the rest of the nerve remaining at the normal level. The terminal increase of PGI did not, contrary to that of AChE, depend on the length of the isolated segment.The changes in PGI activity may be features of a local peritraumatic reaction whereas those of AChE indicate involvement of the whole segment along which the enzyme containing organelles are transported.
WALLERIAN DEGENERATION: A SEQUENTIAL PROCESS
Authors: Simon R. G. , Wade R. R. , DeLarco J. E. , Baker May‐Louise 
Published: October 2006

Abstract—A study of Wallerian degeneration as a function of time has indicated that the degenerative process is sequential, that it begins with myelin that was laid down last and progresses toward myelin that was laid down first. It is proposed that Wallerian degeneration is a relatively poor model for the study of degeneration of nervous tissue in many pathological conditions.
INFLUENCE OF THYROID ON FORMATION OF MYELIN LIPIDS 1
Authors: Walravens P. , Chase H. P. 
Published: October 2006

Abstract—The formation of lipids found primarily in the myelin sheath was investigated in rats made hypothyroid, at birth. A marked reduction in cerebroside, sulphatide, and cholesterol of brains was found in 18‐day‐old hypothyroid animals. These lipids were also reduced, although to a lesser degree, in 30‐day‐old ex‐hypothyroid animals allowed to return to the euthyroid state at age 18 days.The onset of formation of sulphatide in vivo was delayed in the hypothyroid animals. Sulphatide formation reached a peak at a later time and was greatly reduced in comparison to control animals. The activity in vitro of galactolipid sulphotransferase, which forms sulphatide from cerebroside and PAPS, was reduced only when exogenous PAPS was not added to the assay medium. This finding suggests a defect in the formation of PAPS from ATP and sulphate in the hypothyroid brain. In addition, T3 (tri‐iodothyronine) had a stimulatory effect in vivo of formation brain sulphatide when administered to rats during the first 5 days of life.
TRITON SOLUBILIZED ACETYLCHOLINESTERASE OF BRAIN
Authors: Ho I. K. , Ellman G. L. 
Published: October 2006

Abstract—The total AChE of brain can be readily extracted into aqueous Triton X‐100. By column chromatography of these extracts a preparation was obtained at least six times as active as the original material and in yields of 60‐80 per cent of the original amounts. The molecular weight of this material was estimated to be over 200,000. When brain tissue was treated with venom or bacterial protease, a water‐soluble AChE was obtained with an overall purification of 150‐fold. The most active preparation of AChE hydrolysed 880 μ‐moles of acetylthiocholine/hr/mg of protein. The molecular weight of this preparation was estimated to be about 100,000. The enzyme which was extracted by Triton X‐100 is probably the precursor of the more water‐soluble enzyme that can be prepared from brain tissue by treatment with venom or protease.
DNA AND DNA‐POLYMERASE ACTIVITY IN CHICKEN BRAIN REGIONS DURING ONTOGENY1
Authors: Margolis F. L. 
Published: October 2006

Abstract—

The DNA content of cerebral hemispheres, optic lobes, cerebellum and remainder was determined in chicken brains from the 11th day of embryonic life to 6 weeks after hatch. Each region showed a characteristic pattern of variation during development. The cerebellum showed the most rapid and the optic lobes the least rapid rate of DNA increase during the period studied. The concentration of DNA within these regions decreased continuously with age except for that of the cerebellum which passed through a maximum just before hatching.
The nature of the DNA‐polymerase activity in soluble extracts from these brain regions seemed to be similar to the properties reported for this enzyme activity in other vertebrate tissues. Glycerol was stimulatory and denatured DNA was preferred to native DNA as primer. The requirements for magnesium ions and DNA were absolute. The requirement for deoxynucleoside triphosphates indicated this to be a replicative rather than a terminal addition enzyme. At nearly every age the level of enzyme activity was highest in extracts from the embryonic cerebellum.
The particulate fraction from brain homogenates decreased the DNA‐polymerase activity observed in soluble brain extracts. Data are presented which indicate that this inhibition was the result of dephosphorylation of the deoxynucleoside triphosphate substrates by an ATPase in the brain particulate fraction whose activity increases during ontogeny.
STIMULATION OF PIRIFORM‐ AND NEO‐CORTICAL TISSUES IN AN IN VITRO FLOW‐SYSTEM: METABOLIC PROPERTIES AND RELEASE OF PUTATIVE NEUROTRANSMITTERS
Authors: McIlwain H , Snyder S. H 
Published: October 2006

Abstract— (1) Multiple samples from the piriform cortex and neocortex of the guinea pig were maintained in separate incubation vessels through which incubation solutions based on Krebs‐Ringer bicarbonate glucose media were caused to flow for chosen periods at specified rates.(2) The tissues were held in defined positions in relation to electrodes; in some experiments electrical stimuli were applied and in others incubation media were changed with respect to their oxygen, K+ or glutamate content.(3) With media flowing at 3–4 ml/min, the incubated tissues were similar in contents of K salts and phosphocreatine, and in rate of glycolysis to those incubated in non‐flowing media. The tissues responded to electrical stimulation by increase in glycolysis and decrease in phosphocreatine and K content.(4) During pre‐incubation periods in non‐flowing media, samples of piriform cortex were exposed to solutions containing 3H‐labelled glycine, noradrenaline or 5‐hydroxytry‐ptamine and on anlaysis were found to contain the labelled compounds at concentrations four to seven times those of the surrounding media. The labelled compounds were gradually released into the flowing incubation media, and the release of noradrenaline and 5‐hydroxytryptamine was accelerated by electrical stimulation.(5) Release of the two bases was also modified by added reagents and the course of their release is discussed in relation to other metabolic changes concomitantly observed.
INFLUENCE DE LA DEFICIENCE THYROIDIENNE SUR L'INCORPORATION IN VIVO DE LA l‐[3H]LEUCINE DANS LES PROTEINES DU CERVELET CHEZ LE JEUNE RAT THE EFFECT OF THYROID DEFICIENCY ON THE INCORPORATION OF l‐[3H]LEUCINE INTO PROTEINS OF THE CEREBELLUM IN THE YOUNG RAT
Authors: Dainat J , Rebiere A , Legrand J 
Published: October 2006

Résumé— L'incorporation de la leucine dans les protéines du cervelet de jeunes rats normaux et rendus hypothyroïdiens dès la naissance par le propylthiouracile (PTU) a étéétudiée pendant la demi‐heure qui suit l'injection intraveineuse d'une dose de l‐[4‐3H]leucine proportionnelle au poids du corps. Chez les animaux hypothyroïdiens, à tous les stades étudiés (6,10,14 et 21 jours), les radioactivités spécifiques (RAS) des phases acido‐solubles du plasma et du cervelet sont plus élevées que chez les témoins. La RAS des protéines du cervelet est inférieure à 6 jours, 10 jours et 14 jours. La signification de cette diminution de l'incorporation de la leucine tritiée dans les protéines du cervelet est discutée en fonction des données d'ordre structural concernant le développement du cervelet chez l'animal hypothyroïdien.Abstract—The incorporation of leucine into the proteins of the cerebellum of young rats, normal and made hypothyroid since birth by propylthiouracil (PTU), was studied during the half hour following the intravenous injection of a single dose of l‐[4‐8H]leucine proportional to the body weight. In the hypothyroid animals, at all stages studied (6, 10, 14 and 21 days), the specific activity of the label in the free leucine pool of the plasma and cerebellum was higher than in the controls. The specific activity of the cerebellar proteins was lower at 6, 10 and 14 days. The significance of this decrease in the incorporation of tritiated leucine into the cerebellar proteins is discussed in relation to the anatomical data concerning the development of the cerebellum in the hypothyroid animal.
RELATIONSHIP OF PHENYLALANINE TO SEIZURE THRESHOLD DURING MATURATION
Authors: Gallagher B. B. 
Published: October 2006

Abstract—The effect on seizure threshold of the acute intraperitoneal administration of dl‐phenylalanine in varying doses to the albino rat at different ages was investigated. Seizure threshold was measured by the technique using the volatile convulsant, hexafluorodiethylether. The alterations in seizure threshold associated with administration of the amino acid were correlated with blood and brain levels of phenylalanine and tyrosine. In 3‐ to 4‐week‐old albino rats the reduction in seizure threshold was directly related to the amount of phenylalanine administered. The effect was detected at 30 min after injection and had returned to control levels by 2 hr after administration of 20 or 40 mg of Dl‐phenylalanine and by 3 hr following the injection of 80 mg. There was a decreasing susceptibility to reduction in seizure threshold associated with phenylalanine administration with increasing age of the animals. The time course of reduction in seizure threshold in the youngest animals was temporally related more to the rise and fall of concentrations of phenylalanine in brain than to plasma levels of phenylalanine. The seizure threshold in 10‐week‐old animals was not reduced in spite of comparable elevation of blood and brain phenylalanine to the levels effective in 3‐ to 4‐week‐old animals. The results have been discussed in relation to previous studies on chronic, oral administration of phenylalanine to the rat and to possible mechanisms of action.