bluuebunny/crossref_metadata_2025_split huggingface dataset:
VARIATIONS AU COURS DES DIX PREMIERS JOURS DE LA VIE POSTNATALE DE L'INCORPORATION IN‐VIVO DE LA L‐[3H]LEUCINE DANS LES PROTEINES DU CERVELET DU RAT NORMAL, HYPO‐ ET HYPERTHYROIDIEN
Authors: Dainat J. , Rebiére A. 
Published: October 2006

Résumé—L'incorporation de la leucine tritié dans les proteines du cerveau et du cervel et de rat est mesuré 30min aprés l'injection intraveineuse de cet acide aminé marqué. Chez les rats normaux la radioactivité spécifique (RAS) et la RAS relative des protéines du cervelet et du cerveau, varient trés fortement d'un jour à l'autre durant les dix premiers jours de la vie postnatale du rat. Ces variations font ressortir un maximum de la RAS et de la RAS relative des proteines à 7 jours, et deux minima à 3 et 6 jours. Chez les animaux hypothyroïdiens, la RAS et la RAS relative des protéines du cervelet ct du cervcau sont inférieures à celles des animaux normaux. La RAS présente un maximum à 7 jours et un minimum à 3 jours. Chez les animaux hyperthyroidiens, la RAS relative des protéines du cervelet sont significativement plus élevées que celles des animaux normaux. Elks passent par deux maxima à 2 et 5 jours et un minimum à 9 jours. Chez les animaux hypothyroydïdiens comme chez les animaux normaux bien qu'a un niveau inférieur, les synthéses protéiques sont plus importantes durant la deuxième semaine postnatale que durant la première. Par contre chez les animaux hyperthyroïdiens les synthèses protéiques sont plus importantes durant la premiere semaine postnatale que durant la seconde. L'évolution des valeurs de la RAS et de la RAS relative des protéines du cervelet est discutee en fonction des phénomenes de croissance et de prolifération cellulaires. Alors que l'hyperthyroïdie avance ces deux processus sans modifier la durée qui les sépare, l'hypothyroidie en modifiant cette durée, entraîne une perturbation dans le déroulement de ces phénoménes.
METABOLIC PROPERTIES OF A PURIFIED PREPARATION OF LARGE FRAGMENTS OF THE CEREBELLAR GLOMERULI: GLUCOSE METABOLISM AND AMINO ACID UPTAKE
Authors: Wilson J. E. , Wilkin G. P. , Balazs R. 
Published: October 2006

Abstract—Glomerulus particle preparations contain large fragments of the cerebellar glomeruli and are composed almost exclusively of well‐defined neuronal processes (Balázs et al., 1975). The metabolic competence of the glomerulus particles was demonstrated by their ability to convert [14C]glucose to 14CO2 and lactate at a linear rate for over 1 h. The preparations also transported deoxyglucose via an high affinity uptake system (KT= 0.2‐0.5 mM).The kinetics of uptake of various labelled amino acids were also studied. Apparently high affinity uptake systems (KT values about 10‐5 M) were found for thc putative transmitters GABA, glycine, glutamate, and aspartate, but not for leucine, serine, and tyrosine. The maximal velocity of high affinity uptake was the greatest for GABA (about 15 nmol/mg protein per 10 min), while glycine was taken up at about 50%, and aspartate and glutamate at only 13% of the rate obtained with GABA. High affinity uptake of glycine required Na+ (half maximal uptake at 70 mM‐NaCl). Inhibition of glucose transport and glycolysis, electron transport, or oxidative phosphorylation also depressed high affinity uptake of glycine. 2,4‐Diaminobutyric acid was a potent competitive inhibitor of GABA uptake (K1 approx 22 μM), while β‐alanine and glycine had a relatively minor inhibitory effect on the uptake of GABA.
ELECTRICALLY INDUCED RELEASE OF [3H]GABA FROM NEOCORTICAL THIN SLICES. EFFECTS OF STIMULUS WAVEFORM AND OF AMINO‐OXYACETIC ACID
Authors: Orrego F. , Miranda R. 
Published: October 2006

Abstract—The efflux of [3H]GABA or [14C]GABA from superfused neocortical thin slices, held on quick transfer electrodes, has been compared with that of the non‐transmitter amino acid model [14C]α‐ amino‐isobutyrate (AIB), and, to a lesser extent, with [3H]norepinephrine. Electrical stimulation of the slices with sine‐wave current (50 Hz); rectangular, biphasic pulses, (80/s, 3 ms); or rectangular, monophasic pulses (100/s, 5 ms), was unable to release GABA at stimulating potentials that are able to release known transmitter substances. Release of GABA and AIB was only seen with higher applied potentials, when also non‐transmitter amino acids were released. It was also found that amino‐oxyacetic acid(10‐5 M and 5 × 10‐5 M) increased the excitability of the slices, and allowed the release of both GABA and AIB to occur with weaker stimuli. This effect was independent of extracellular calcium.
ANISOMYCIN, ACETOXYCYCLOHEXIMIDE, CYCLOHEXIMIDE, AND PUROMYCIN AS INHIBITORS OF RAT BRAIN ACETYLCHOLINESTERASE IN VITRO1
Authors: Moss D. E. , Fahrnly D. 
Published: October 2006

AbstractA kinetic analysis of the interaction of anisomycin, acetoxycycloheximide, cycloheximide, and puromycin with acetylcholinesterase (acetylcholine acetyl‐hydrolase, EC 3.1.1.7) in rat brain homogenate shows that all of these protein synthesis inhibitors are also inhibitors or this enzyme. Puromycitl aminonucleoside, a puromycin analog without antibiotic activity, was also found to be an inhibitor of acetylcholinesterase activity much like puromycin. Anisomycin appeared to be a competitive inhibitor whereas all of the other compounds showed mixed inhibition. The apparent 10.5 values for inhibition of rat brain acetylcholinesterase at 50 μM substrate were: anisomycin, 3 mM; acetoxycycloheximide, 1 mM; cycloheximide, 2.2 mM; puromycin, 0.5 mM and puromycin aminonucleoside, 0.6 mM.
REGIONAL AND SUBCELLULAR DISTRIBUTION OF PROTEIN CARBOXYMETHYLASE IN BRAIN AND OTHER TISSUES
Authors: Diliberto E. J. , Axelrod J. 
Published: October 2006

AbstractProtein carboxymethylase, an enzyme that transfcrs the methyl group of S‐adenosyl‐L‐methionine to carboxyl groups of proteins and endogenous acceptor proteins were examined in nerve and endocrine tissues. The highest protein carboxymethylase activity was found in the brain, followed by the testis, pituitary and heart. On the other hand, the tissue with the highest level of endogenous substrate(s) was the pituitary. The nearly identical specific activity ratio for two different protein substrates in all tissues examined, suggests that one enzyme is responsible for carboxymethylase activity in different tissues. The subcellular distribution of the enzyme in brain showed a high concentration in the soluble fraction, presumably representative of the enzyme in the cytosol of cell bodies. Considerable enzyme activity was also found in brain synaptosomes which was increased by osmotic lysis. Protein carboxymethylase was shown to accumulate proximally to a ligation of the rat sciatic nerve. A possible physiological role for protein carboxymethylase in neuronal function is discussed.
THE DISTRIBUTION AND METABOLISM OF PUTRESCINE, SPERMIDINE AND SPERMINE INJECTED INTO THE CEREBRAL VENTRICLES OF RABBITS
Authors: Halliday C. A. , Shaw G. G. 
Published: October 2006

AbstractFollowing the intracerebroventricular injection into rabbits of spermidine or spermine the highest concentrations were initially found in the caudate nucleus, hypothalamus and medulla. Subsequently there was a rapid decline in the amounts present in the caudate nucleus and hypothalamus and, particularly in the case of spermidine, an increase in the conccntration in the lower brain stem and cervical cord. This pattern of changes is consistent with the amines being redistributed by passage in CSF. Intraventricularly injected putrescine followed the same initial distribution pattern but within 2 days it had been largely converted to spermidine and spermine. Synthesized polyamines accumulated in all the regions examined. The time course of synthesis indicated that spermidine was the precursor of spermine. Spermine was also formed from injected spermidine and vice‐versa. These findings concur with the pharmacological and neurotoxic actions of putrescine, spermidine and spermine.
PHARMACOLOGICAL STUDIES ON THE STIMULATION OF THE PHOSPHOLIPASE A2‐ACYLATION SYSTEM OF SYNAPTIC MEMBRANES OF BRAIN, BY NEUROTRANSMITTERS AND OTHER AGONISTS
Authors: Gullis R. J. , Rowe C. E. 
Published: October 2006

AbstractMethacholine, nicotine and succinylcholine stimulated the phospholipase A2‐acylation system of synaptic membranes isolated from the cerebral cortex of guinea pig. Stimulation by acetylcholine was partially blocked by atropine and by D‐tuberocurarine respectively, indicating both muscarinic and nicotinic stimulation. Muscarinic stimulation by acetylcholine was greater than ‐isotinic stimulation, and stimulation by acetylcholine was completely blocked by a combip, or;. and n‐tuberocurarine.The phospholipase A2‐acylat tem was stimulated by phenylcphrine., id. Cqxoterenoi. Stimulation by noradrenaline was J‐. tidlr, by phenoxybenzamine and pindalol i:spectively, indicating both 8‐adrenergic and P‐adrenergic ztimulation. n‐Adrenergic stimulation by noradrenaline was greater than P‐adrenergic‐stimulation. 5 ‐mlation by noradrenaline was completely blocked by a combination of phenoxybenzamins and pindalol.Stimulation of both acylation and phospholipid hydrolysis, by 5‐hydroxytryptamine and histamine were partially blocked by methysergide and diphenhydramine respectively. Stimulation by dopamine was blocked by halopcridol. Stimulation by y‐aminobutyric acid was partially blocked by strychnine and by picrotoxin.Dichloroisoproterenol, atropine, methysergidr, diphenhydramine, strychnine, picrotoxin and eserine, at relatively high concentrations (1 mM), stimuhted the phospholipase A2‐acylation system.Synergistic stimulations of both acylatior, and hydrolysis of phosphatidylcholine, were observed by adenosine combined with noradrenaline, 5‐hydroxytryptamine, histamine, dopamine or yaminobutyric acid, respectively.In the presence of ATP‐MgCI, synergistic stimulations of the hydrolysis of phosphatidyicholine were observed after 30 s by noradrenaline combined with 5‐hydroxytryptamine, histamine, dopamine, aminobutyric acid or carbamoylcholine respectively. In the presence of GTP‐MgC12 synergistic stimulations were obtained by cdrbamoylcholine combined with noradrenaline. 5‐hydroxytryptamine. histamine, dopamine or y‐aminobutyric acid, respectively. In the presence of ATP‐MgC12 plus GTP‐MgC12, stimulation by noradrenaline and one other agonist including 5‐hydroxytryptamine, histamine, dopamine, y‐aminobutyric acid or carbamoylcholine were close to additive.
EFFECT OF ACIDIC DEOXYRIBONUCLEOPROTEINS FROM BRAIN ON DNA SYNTHESIS IN VITRO
Authors: Burdman J. A. , Szijan I. 
Published: October 2006

AbstractChromatin acidic proteins extracted from rat brain stimulate in uitro synthesis of DNA with either brain chromatin. native or denatured DNA as template.The stimulation is due to the presence of nuclease activity within these proteins which increases the priming activity of DNA.
DIVALENT CATION‐ACTIVATED ECTO‐NUCLEOSIDE TRIPHOSPHATASE ACTIVITY OF NERVOUS SYSTEM CELLS IN TISSUE CULTURE
Authors: Stefanovic V. , Léadig M. , Mandel P. 
Published: October 2006

Abstract— Intact neuroblastoma and glial cells in monolayer culture hydrolysed ATP added to their medium. Evidence is presented that ATP is cleaved outside of the permeability barrier of the plasma membrane and the product is liberated in the extracellular medium, i.e. the enzyme is an ecto‐enzyme. Divalent cations such as Mg2+, Ca2+, Mn2+ and Co2+ activate the enzyme. In neuroblastoma cells, Ca2+ is the preferential cation for activation; Mg2+ in glial cells. Substrate specificity was very low when different nucleoside‐5′‐triphosphates were examined. Competition studies have revealed that all of the nucleoside triphosphates are hydrolysed by the same enzyme: divalent cation‐activated ecto‐nucleoside‐5′‐triphosphate phosphohydrolase.Developmental pattern of the enzyme in several lines was established. The role of enzyme in the transport of divalent cations across the plasma membrane and/or in the physical properties of the membrane is suggested.
PROTEIN PHOSPHORYLATION IN VITRO IN BRAIN TUBULIN PREPARATIONS: EFFECTS OF Zn2+ AND CYCLIC NUCLEOTIDES
Authors: Larsson H. , Edström A. , Wallin Margareta 
Published: October 2006

Abstract— Endogenous protein phosphorylation has been studied during in vitro polymerization of microtubules by incubating a purified tubulin preparation at 37°C in the presence of radioactive ATP. At optimal conditions the rate of phosphorylation was found to follow the course of polymerization by a shift to a lower rate at the polymerization plateau.Zn2+ at 0.5 mm was shown to stimulate phosphorylation, mainly of tubulin‐associated proteins (mol wt 110,000 and 175,000,) and to a lesser extent of tubulin. The effect occurred at Zn2+‐concentrations which induce formation of tubulin sheet polymers, which suggests that the state of aggregation of tubulin is of importance for the phosphorylation. In contrast to Zn2+, Mg2+ only increased phosphorylation of the high molecular weight proteins, and to a lesser degree. The stimulation by Zn2+ or Mg2+ was potentiated by cyclic AMP or cyclic GMP.A low concentration of Zn2+ (5 μm) or cyclic GMP at 10 μm inhibited phosphorylation, possibly by interaction with a co‐existing protein phosphatase.
SIALYLTRANSFERASES IN RAT BRAIN: REACTION KINETICS, PRODUCT ANALYSES, AND MULTIPLICITIES OF ENZYME SPECIES
Authors: Ng S.‐S. , Dain J. A. 
Published: October 2006

Abstract— The incorporation of NeuNAc from CMP‐NeuNAc into endogenous glycolipids and glyco‐proteins, and exogenously added GM1a (monosialoganglioside) and desialylated fetuin (DS‐fetuin) was studied with particulate preparations from 11 to 15 day old rat cerebra. The apparent +K++m values of the enzyme systems for the different substrates, assayed with 0.5 mg enzyme protein, were: CMP‐NeuNAc, 0.13 mm (same with endogenous and exogenous glycolipid and glycoprotein substrates); GM1a, 0.20 mm; DS‐fetuin, 0.15 mm (or 1.2 mm in terms of acceptor sites). The activities, expressed as nmoles NeuNAc incorporated per 0.5 mg enzyme protein per 30 min incubation at 37°C and pH 6.3, were 0.094, 0.039, 0.17 and 0.64 with the endogenous glycolipids, endogenous glycoproteins, exogenous GM1a and exogenous DS‐fetuin, respectively. Incorporation into endogenous glycolipids was mainly in GM3, while exogenously added GM1a was converted to GD1a. Incorporation into endogenous glycoproteins yields about 20 sialoglycopolypeptides on SDS‐polyacrylamide gel electrophoresis. Neura‐minidase pretreatment of the particulate enzyme preparation decreased sialylation of the higher molecule weight polypeptides but increased sialylation of the lower molecule weight species.The sialyltransferase activity with the endogenous glycolipid substrates was more heat resistant than the activities with exogenous GM1a. Since more than 60% of the endogenous glycolipid activity was due to the conversion of lactosylceramide to GM3, the sialyltransferase responsible for this reaction appears to be different from the one that acts on GM1a. This was supported by the observation that exogenously added GM1a did not diminish the incorporation of NeuNAc into endogenous lactosylceramide. These two glycolipid sialyltransferase activities were distinguishable from the glycoprotein sialyltransferase activity since exogenous DS‐fetuin did not compete with either the endogenous or the exogenous glycolipids for CMP‐NeuNAc.
CHANGES IN SPECIFIC ACTIVITY OF DOPAMINE METABOLITES AS EVIDENCE OF A MULTIPLE COMPARTMENTATION OF DOPAMINE IN STRIATAL NEURONS
Authors: Groppetti A. , Algeri S. , Cattabeni F. , Di Giulio A. M. , Galli C. L. , Ponzio F. , Spano P. F. 
Published: October 2006

Abstract—The functional status of dopaminergic nerve terminals has been studied with a method that allows the simultaneous determination of the specific activities of dopamine (DM), tyrosine (Tyr), 3‐methoxytyramine (3‐MT) and 3,4‐dihydroxyphenylacetic acid (DOPAC), after administration of [3H]tyrosine ([3H]Tyr).Combined fluorimetric, mass fragmentographic and radiometric techniques have been used. [3H]Tyrosine was given intraventricularly to unanaesthetized rats and the animals were killed by exposure for 4 s to high energy microwave radiations.The specific activities of 3‐MT and DOPAC measured 5 and 20 min after administration of [3H]Tyr, i. e. at time intervals in which the specific activity of DM is rising, are much higher than those their physiological precursor, suggesting that they are generated by more than one DM compartment.This hypothesis seems to be supported by the finding that in animals killed by decapitation instead of microwave radiations the post mortem accumulation of 3‐MT occurs to a much smaller extent for the radioactive fraction than for the endogenous one, indicating that 3‐MT formed after death may be mainly derived from DM coming from a compartment where this monoamine has been poorly labeled by the radioactive precursor.
INTERRELATION OF PHOSPHOINOSITIDE METABOLISM AND ION TRANSPORT IN CRAB NERVE FIBRES1
Authors: Tret'jak A. G. , Limarenko I. M. , Kossova G. V. , Gulak P. V. , Kozlov Yu. P. 
Published: October 2006

Abstract—The effects of acetylcholine (ACh) on phosphoinositide metabolism and associated changes in nerve fibre membranes of Carcinus maenas and Eriphia spinifrons were studied. It was shown that as the content of triphosphoinositide in ACh‐treated crab nerve fibre decreased, the permeability of the fibres to K+ increased, which led to nerve fibre depolarization. Proserini protected nerve fibres against the effect of ACh. These observations appear to implicate the participation of acetylcholinesterase in triphosphoinositide hydrolysis. Our results indicate that phosphoinositides participate in the control of the permeability of crab nerve fibres to potassium ions.
EFFECTS OF PROTECTION OF BUTYRYLCHOLINESTERASE ON REGENERATION OF GANGLIONIC ACETYLCHOLINESTERASE
Authors: KOELLE WINIFRED ANGENENT , SMYRL ELOISE GABEL , RUCH G. A. , SIDDONS VERA E. , KOELLE G. B. 
Published: October 2006

Abstract—The regeneration of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) was followed in the superior cervical (SCG), stellate (StG), and ciliary (CG) ganglia and inferior oblique (IO) muscle of cats for the 3‐day period following their inactivation by isopropylmethylphosphonofluoridate (sarin; 2.0 μmol/kg intravenously), with and without preservation of over half the butyrylcholinesterase activity by the prior intravenous infusion of 10‐(α‐diethylaminopropionyl) phenothiazine HCl (Astra 1397; 100 or 200 μmol/kg). Rates of regeneration of AChE in the three ganglia exhibited the same sequence as their relative proportions of AChE‐containing cholinergic ganglion cells (SCG < StG < CG); no such difference was found in the rates of butyrylcholinesterase regeneration. The mean AChE levels in all three ganglia were higher at 48 h in the cats that had received Astra 1397 (100 μmol/kg) prior to sarin. This finding is interpreted as evidence that BuChE may function as a precursor in the synthesis of AChE.
CHICK BRAIN CREATINE KINASE ONTOGENY BEFORE THE ADVENT OF CREATINE AND INSULIN
Authors: RAMIREZ O. , TAKAHASHI J. , HERNANDEZ MARGARITA 
Published: October 2006

Abstract—The ontogeny of brain creatine kinase (CK) was studied during chick embryo development. The cytosolic activity increased 270% in 10 h from the 2nd to the 3rd days of incubation; this was followed by a plateau phase throughout development and at the end of incubation there appeared to be another increase of cytosolic and mitochondrial CK activities. Therefore, early embryonic chick brain CK is another‘constitutive’enzyme like the early embryonic chick heart CK since creatine has not been enzymatically detected in the embryo until day 4 of incubation. Insulin does not appear to stimulate the early increase of brain CK activity since the hormone is not present in the embryo until day 5 of incubation. It is likely that CK increase is associated with neuronal multiplication at early stages and possibly to neuronal maturation before hatching.
PYRUVATE DEHYDROGENASE ACTIVATION IN RAT BRAIN CORTICAL SLICES BY ELEVATED CONCENTRATIONS OF EXTERNAL POTASSIUM IONS
Authors: Kovachich G. B. , Haugaard N. 
Published: October 2006

Abstract— Cortical slices from rat brain were incubated in Krebs‐Ringer phosphate medium. Activity of the pyruvate dehydrogenase complex (PDH) was measured in homogenates of the incubated tissue. Increasing the extracellular KCI concentration from 5 to 75 mM caused a dose‐dependent increase in activity of this rate‐limiting mitochondrial enzyme. The increase in PDH activity, produced by high concentration of KCI. was associated with a decrease in the tissue content of ATP. Omission of calcium, or replacement of sodium by choline, reduced, and addition of ouabain prevented, the activation of the enzyme in the depolarized tissue.The mechanism by which extracellular potassium can affect PDH activity is unknown. However, it is most likely that the alterations in enzyme activity are related to changes in properties of cell membranes during depolarization leading to intracellular events directly affecting the enzyme complex. These could include alterations in the concentrations of adenine nucleotides or free calcium ions in the cell.
EFFECT OF PRETREATMENT UNDER VARIOUS CATIONIC CONDITIONS ON ACETYLCHOLINE CONTENT AND CHOLINE TRANSPORT IN RAT WHOLE BRAIN SYNAPTOSOMES
Authors: Weiler M. H. , Jope R. S. , Jenden D. J. 
Published: October 2006

AbstractThe effects of different ionic environments were measured on the concentration of acetyl‐choline (ACh) from synaptosomes and their effect on subsequent high affinity choline (Ch) transport and ACh synthesis after resuspension of the synaptosomes in the normal Krebs medium. KCl (40 mM) was used to induce ACh release and reduce synaptosomal ACh content. The effects of Na+ omission, Ca2+ omission, and high Mg2+ on spontaneous (KC1: 4.75 mM) and potassium induced (KC1: 40 mM) ACh release and other cholinergic parameters are presented. The high affinity transport of Ch was more highly correlated with the reciprocal of the ACh level (r= 0.934, P= 9.7 × 10‐4) than with the ACh release rate during preincubation (r= 0.792, P= 3.4 × 10‐2). The results are consistent with the view that the consequences of the various ionic conditions on Ch transport and ACh synthesis are dependent on their effects on intrasynaptosomal ACh levels and only secondarily on synaptosomal ACh release.
GLYCOPROTEIN CHANGES DURING THE DEVELOPMENT OF HUMAN BRAIN
Authors: Federico A. , Benedetta C. Di , Milici N. 
Published: October 2006

AbstractBrain glycoprotein sugars were studied during human brain development. Marked changes were found in the sugar content of glycopeptides derived from soluble and insoluble glycoproteins, showing a general decrease in the soluble and an increase in the insoluble fraction. The data indicate that changes in glycan moiety and/or in glycoprotein population occur during development. The existence of a‘critical period’in glycoprotein development which coincides with the formation of axonal and synaptic membranes sprouting has been established (Dobbing, 1971).