bluuebunny/crossref_metadata_2025_split huggingface dataset:
TRANS‐SULPHURATION IN PRIMATE BRAIN: REGIONAL DISTRIBUTION OF METHIONINE‐ACTIVATING ENZYME IN THE BRAIN OF THE RHESUS MONKEY AT VARIOUS STAGES OF DEVELOPMENT
Authors: Volpe J. J. , Laster L. 
Published: October 2006

Abstract—The regional distribution of methionine‐activating enzyme (ATP:l‐methionine S‐adenosyltransferase; EC 2.4.2.13) in the brain of the Rhesus monkey was determined at various stages of development.Activity of the methionine‐activating enzyme was highest in pituitary gland, cerebellum and occipital grey matter, and lowest in areas rich in white matter: spinal cord, subcortical white matter, corpus callosum and optic chiasm. There was no marked change in activity in any area during development from the first‐trimester foetus to the juvenile animal. During the same period of development, activity of the methionine‐activating enzyme in the liver increased approximately four‐fold.The findings are discussed in relation to those transmethylating enzymes and/or methylated products which have been studied in mammalian brain. The presence of high activity of the methionine‐activating enzyme in cerebellum and occipital grey matter suggests that previously unrecognized methylating processes may be important in the metabolism of these areas of brain.
The influence of adrenergic and cholinergic blocking drugs on the glycogen content of the brain in rats deprived of paradoxical sleep
Authors: Mršulja B. B. , Rakić L. M. 
Published: October 2006

Recent studies have pointed out biochemical and pharmacological phenomena associated with the mechanism or mechanisms of sleep, especially in its paradoxical phase (Jouvet, 1964; Mandel, 1964). Our previous experiments have shown that paradoxical sleep (PS) deprivation leads to the fall of total glycogen content in certain regions of the brains of cats (Mršulja, Rakić and Radulovački, 1967; Mršulja and Rakić, 1968) and rats (Karadžič and Mršulja, 1969). It was shown that changes of glycogen content correspond to PS deprivation and that PS deprivation is a specific stress to which the CNS responds selectively. Alterations in the glycogen concentration in a number of different brain structures lead us to conclude that neural areas affected by PS deprivation are widely distributed.Jouvet (1962) was one of the first to suggest that a neurohumoral mechanism may be concerned in the control of and characteristics of sleep. Experiments have shown that both cholinergic and adrenergic mechanisms may be involved in the initiation, maintenance and control of sleep. It has also been pointed out that paradoxical sleep can be started and maintained by cholinergic drugs (Matsuzaki, Okada and Shuto, 1967, 1968), blocked or reduced by anticholinergic compounds (Matsuzaki et al., 1968), and stimulated by noradrenaline or by its precursor, DOPA (Matsumoto and Jouvet, 1964).Bowers, Hartmann and Freedman (1966) showed that the ACh level of the rat telencephalon decreases with PS deprivation while the levels of norpinephrine and serotonin remain the same (Barchas and Freedman, 1963). More recently, Pujol, Mouret, Jouvet and Glowinski (1968) found the increased turnover of cerebral norepinephrine during rebound of PS in the rat.It is also of interest to point out that probably both adrenergic and cholinergic processes participate in the glycogenolytic effect of physostigmine (Mršulja, Terzić and Varagić, 1968). It was suggested that physostigmine initiates the cholinergic processes which then trigger off adrenergic processes.The aim in the present work was to determine the glycogen content in certain brain regions of rats which were subjected to PS deprivation lasting 72 hr and treated with some cholinergic or beta‐adrenergic blocking agents, as well as with a catecholamine depleting drug.
EFFECTS OF NARCOTICS ON THE GIANT AXON OF THE SQUID1
Authors: Simon E. J. , Rosenberg P. 
Published: October 2006

Abstract—Levorphanol (10‐3 M) reversibly blocked conduction in the giant axon of the squid and axons from the walking legs of spider crab and lobster. Similar concentrations of levallorphan and dextrorphan blocked conduction in the squid giant axon. Under the same experimental condition morphine caused an approximately 40 per cent decrease in spike height. Levorphanol did not affect the resting potential or resistance of the squid axon. Spermidine, spermine and dinitrophenol had little or no direct effect on the action potential nor did they alter the potency of levorphanol. Concentrations of levorphanol as low as 5 × 10‐5 M blocked repetitive or spontaneous activity in the squid axon induced by decreasing the divalent cations in the medium. After exposure to tritiated levorphanol, the axoplasm and envelope of the squid axon accumulated up to 500 per cent of the concentration of tritium found in the external medium, dependent on time of exposure, and other variables. At pH 6 the levels of penetration were 33‐50% of those found at pH 8, which correlates with our observation that levorphanol is about 33 % as potent in blocking the action potential at pH 6. The penetrability of levorphanol was not affected by spermidine, dinitrophenol or cottonmouth moccasin venom. Levorphanol did not alter the penetration of [C14]acetylcholine nor did it render the squid axon sensitive to it. The block of axonal conduction by compounds of the morphine series is discussed both as to possible mechanisms and significance.
EFFECTS OF NERVE STIMULATION ON THE METABOLISM OF RIBONUCLEIC ACID IN A MOLLUSCAN GIANT NEURONE
Authors: Price Peterson R. , Kernell D. 
Published: October 2006

Abstract—In vitro experiments were performed in order to determine whether nerve stimulation would affect the RNA metabolism of an identified giant neurone (R2) in the abdominal ganglion of Aplysia californica. The electrophysiological activity of the neurone was continuously monitored with an intra‐ or extracellular microelectrode. The mere presence of an intracellular microelectrode inside the neurone had no significant effect on the incorporation of tritiated nucleosides into the RNA of the giant neurone. Prolonged electrical stimulation of ganglionic nerves, strong enough to elicit post‐synaptic spikes in the giant neurone, produced a marked increase in the amount of labelled RNA in the nucleus as well as in the cytoplasm. Electrophoresis studies suggested that this increase in labelling might concern RNA with molecular weights corresponding to ribosomal as well as to non‐ribosomal RNA.
ACID‐LABILE (AMIDE) NITROGEN METABOLISM OF BRAIN PROTEINS
Authors: Kometiani P. A. , Klein Ye. E. , Gvalia N. V. , Gotsdudze Ye. G. 
Published: October 2006

Abstract—When the TCA‐insoluble fraction of samples of rat brain was extracted with organic (lipid) solvents, a soluble protein fraction was obtained which was metabolically active in the release and uptake of ammonia. The total nitrogen content of this fraction increased during aerobic incubation of slices of cerebral cortex and in brain samples after electrical stimulation of the rats, but under these conditions the content of protein‐bound, acid‐labile (amide) nitrogen decreased. Treatment of rats with intraperitoneally injected camphor caused a decrease in the content of acid‐labile nitrogen both in the proteins extracted into lipid solvents from the TCA precipitate of brain tissue samples and in the residual, washed TCA precipitate. By contrast, after treatment of rats with pentobarbitone, the content of proteinbound, acid‐labile nitrogen increased in the lipid solvent extract but decreased in the residual, washed TCA precipitate. After electrical stimulation of rats, the content of acid‐labile nitrogen in proteins of subcellular particles isolated from homogenates of brain exhibited dissimilar changes from control level: a pronounced decrease in the crude nuclear fraction but no change or a slight increase in the crude mitochondrial and in the combined microsomal and supernatant fractions. When slices of rat brain were incubated aerobically in the presence of glucose, ammonia was transferred from free amino acids to the acid‐labile (amide) nitrogen of protein. Evidence was obtained indicating the participation of aspartate and purine nucleotides in this transfer.
EFFECTS OF ETHANOL ON THE ACTIVITY OF ADENOSINE TRIPHOSPHATASE AND ACETYLCHOLINESTERASE IN SYNAPTOSOMES ISOLATED FROM GUINEA‐PIG BRAIN
Authors: Sun A. Y. , Samorajski T. 
Published: October 2006

Abstract—Nerve ending fractions from guinea‐pig cerebral cortex contained more than one‐half of the Na‐K ATPase activity present in the original homogenate. Ethanol at concentrations ranging from 0·043 to 2·57 m inhibited the Na‐K ATPase to a significantly greater extent than the Mg‐activated ATPase or AChE. The inhibition of membrane‐bound Na‐K ATPase by ethanol was of the non‐competetive type and the activity of Na‐K ATPase was increasingly inhibited by alcohols of increasingly longer chain length. The ability of various alcohols to inhibit membrane‐bound Na‐K ATPase activity was correlated with their lipid solubility.
LACK OF CORRELATION BETWEEN THE ZINC‐IODIDE‐OSMIUM POSITIVITY OF CHOLINERGIC TERMINALS AND THE CHOLINERGIC TRANSMISSION IN THE SYMPATHETIC GANGLIA OF THE CAT
Authors: Pärducz Á. , Halász N. , Joó F. 
Published: October 2006

Abstract—The aim of the experiments was to determine whether a direct correlation exists between cholinergic transmission and zinc‐iodide‐osmium (ZIO) positivity of the synaptic vesicles of the preganglionic terminals in sympathetic ganglia of the cat. It was found that hemicholinium (HC‐3) pretreatment with or without preganglionic stimulation did not cause any significant changes in the ZIO positivity of cholinergic nerve terminals. The authors suppose that there is no direct relation between the ZIO positivity of axon terminals and the functioning of cholinergic transmission.
EFFECT OF CYANIDE AND ELECTRICAL STIMULATION ON PHOSPHOINOSITIDE METABOLISM IN LOBSTER NERVES
Authors: Birnberger Anita C. , Birnberger K. L. , Eliasson S. G. , Simpson P. C. 
Published: October 2006

AbstractThe contents of phosphoinositides, ATP, glucose and lactate in leg and claw nerves of the lobster were determined. Nerves were also analysed after cyanide poisoning, after electrical stimulation, and 1 h after removing the leg from the lobster.Cyanide poisoning decreased the levels of ATP and glucose and increased the content of lactate but did not alter the levels of phosphoinositides. Nerves left in situ for 1 h after disconnection from the central nervous system exhibited a decrease in the content of tri‐phosphoinositides (TPI) of 50 per cent, without changes in ATP, glucose or lactate. The TPI change was reversed after incubation for 1 h in oxygenated seawater.Nerves labelled in vivo with 32P were removed and stimulated at 50 Hz for 5 min. The turnover of TPI phosphorus increased on stimulation in both normal and cyanide‐poisoned nerves. In contrast, turnover of ATP increased after stimulation in normal nerves but not in cyanide‐treated nerves.We sought to determine whether polyphosphoinositides play a greater role in resting metabolism of the nerve or in the conducting mechanisms. Our results make more likely the involvement of TPI in permeability changes of neural membranes during excitation.
MEASUREMENT OF γ‐AMINOBUTYRIC ACID IN ISOLATED NERVE CELLS OF CAT CENTRAL NERVOUS SYSTEM
Authors: Otsuka M , Obata K , Miyata Y , Tanaka Yuriko 
Published: October 2006

Abstract— A sensitive method for measuring γ‐aminobutyric acid (GABA) has been developed. This method consists of a combination of the enzymic GABA assay of Jakoby and Scott (1959) with the enzymic cycling technique of Lowry, Passonneau, Schulz and Rock (1961) and permits the measurement of as little as 2 × 10−14 mol of GABA. Using this method, GABA analyses were made on single isolated nerve cell bodies of different types from the CNS of the cat. Average GABA concentrations in these cell bodies were: spinal ganglion cells, 0.2 mm; spinal mononeurons, 0.9 mm; large cells of the ventral part of Deiters' nucleus, 2.7 mm; large cells of the dorsal part of Deiters’ nucleus, 6.3 mm; cerebellar nuclei cells, 6.0 mm; cerebellar Purkinje cells, 6.6mM; cerebral Betz cells, 2.5 mm.The GABA concentrations in the isolated dorsal Deiters' cells were greatly reduced (1.7 mm) after the removal of the cerebellar vermis while those of the ventral Deiters' cells were unaffected by the denervation. These results suggest that GABA is concentrated within axon terminals, probably of Purkinje neurons, synapsing with the dorsal Deiters' cells. The results of GABA analyses on isolated nerve cells are discussed in relation to the relevant neuronal functions and the possible role of GABA as an inhibitory transmitter.
SEPARATION OF CATECHOLAMINE STORING SYNAPTOSOMES IN COLLOIDAL SILICA DENSITY GRADIENTS
Authors: Lagercrantz H. , Pertoft H. 
Published: October 2006

Abstract— Catecholamine storing particles mainly from rat brain hypothalamus and corpus striatum have been isolated by isopycnic centrifugation in density gradients made of colloidal silica. As markers, tritium‐labelled noradrenaline, endogenous noradrenaline and dopamine were measured. Cytochrome oxidase was determined as an indicator of mitochondria.Two distinct populations of amine containing particles were recognized with densities of 1, 03–1.04 g/ml and 1, 045–1.065 g/ml in continuous isotonic gradients made of silica sol and a polymer. The light fraction was assumed to contain myelin fragments, light synaptosomes and possibly also catecholamine storage vesicles, while the other one was probably a heavy population of synaptosomes containing more mitochondria. Free mitochondria were found in a band at a density of 1, 09–1.11.The distribution pattern in isotonic gradients was compared with that in density gradients made of silica sol and sucrose or sucrose alone. The heavy population of the catecholamine particles was found to have a higher density in hypertonic gradients. Furthermore these synaptosomes seemed to lose more mitochondria and catecholamines than those in isotonic gradients probably due to the hypertonicity.The present results confirm similar findings by other workers separating brain sub‐ cellular particles in isotonic gradients of Ficoll and sucrose.Colloidal silica solutions might be of value for analytical centrifugation of brain sub‐cellular particles, since it has a lower tonicity than sucrose, lower viscosity than Ficoll and furthermore it is very easy to handle. The silica sol is inexpensive and allows large scale work.
PURIFICATION AND PROPERTIES OF MULTIPLE FORMS OF BRAIN ACETYLCHOLINESTERASE (EC 3.1.1.7)1
Authors: Chan S. L. , Shirachi D. Y. , Bhargava H. N. , Gardner E. , Trevor A. J. 
Published: October 2006

Abstract—Approximately 70 per cent of the total AChE of bovine brain tissue was solubilized by repeated homogenization and centrifugation in 0.32 m sucrose containing EDTA. After ammonium sulphate fractionation, application of the enzyme preparation to an agarose affinity gel column effected a 700‐fold purification. Subsequent molecular filtration separated three active forms of AChE with molecular weights of 130,000, 270,000 and 390,000 with an average specific activity of 575 mmol of acetylthiocholine hydrolysed/mg of protein/h. The complete procedure represented an approximate 23,000‐fold purification of the enzyme from that in the original tissue homogenate. The three forms of AChE exhibited certain differences in properties, including apparent Km values, pH optima and sensitivity to inhibitory agents. Ancillary studies on less purified enzyme preparations by use of polyacrylamide gel electrophoresis and isoelectric focusing techniques also suggested that brain AChE exists in multiple forms.
THE INCORPORATION OF LABELLED ACETATE INTO CEREBROSIDE AND OTHER LIPIDS OF THE DEVELOPING MOUSE BRAIN
Authors: Kanazawa I. , Ueta N. , Yamakawa T. 
Published: October 2006

Abstract—Cerebroside in the brain is highly localized in myelin and has a relatively slow turnover rate. The aim of this study was to evaluate the true cerebroside biosynthetic activity under conditions in which the degradation and reutilization of brain lipids were as small as possible. The 3‐week‐old mice were decapitated at 0·5, 1, 2·5, 5 and 15 min after the intraperitoneal injection of labelled acetate and the incorporation of radioactivity into each lipid class was examined. Even at 0·5 min, a considerable amount of radioactivity was found in simple lipids, especially in the free fatty acid fraction, and in the course of time the radioactivity of complex lipids increased. On the other hand, the incorporation of radioactivity into cerebrosides was extremely small throughout the experimental period. Results indicated that the low radioactivity of cerebroside might be due to its high content of long‐chain fatty acids which were weakly labelled. The radioactivity of the sphingosine moiety was also low. In short, one of the rate‐limiting steps of cerebroside synthesis in brain might exist in long‐chain fatty acid and sphingosine synthesis. In addition, the incorporation curves of each component of cerebroside were compared with each other and the difference of the incorporation pattern of non‐hydroxy fatty acids of cerebroside was noted.
REGIONAL CHANGES IN CNS LEVELS OF THE S‐100 AND 14‐3‐2 PROTEINS DURING DEVELOPMENT AND AGING OF THE MOUSE1
Authors: Cicero T. J. , Ferrendelliy J. A. , Suntzeff V. , Moore B. W. 
Published: October 2006

AbstractThe levels of the S‐100 and 14‐3‐2 proteins were determined in a number of regions of mouse brain at intervals from 1 day to 30 months of age. Both S‐100 and 14‐3‐2 were found in measurable amounts as early as the first day of postnatal age but did not begin to accumulate rapidly in the forebrain, brain stem and cerebellum of the mouse brain until some time between the 7th and 14th days. From days 14 to 28 the levels of S‐100 and 14‐3‐2 in each region continued to increase rapidly with the exception of the forebrain where the rate of accumulation of S‐100 appeared to lag considerably behind that in the other regions. The proteins continued to accumulate at a rapid rate until approximately 6 months of age.From 6 to 30 months of age, the levels of 14‐3‐2 remained relatively stable in cerebellum, hippocampus and hypothalamus and appeared to decrease slightly in striatum and cerebral cortex. In the case of S‐100, the level of the protein increased in all regions of brain from 6 to 30 months but the increase was most pronounced in the hippocampus, hypothalamus and striatum. The principal conclusion derived from this study is that the biochemical development and aging of the central nervous system are regionally selective processes.
STUDIES ON CEREBRAL ENERGY METABOLISM DURING THE COURSE OF GALACTOSE NEUROTOXICITY IN CHICKS1
Authors: Granett Sandra E. , Kozak L. P. , McIntyre Jean P. , Wells W. W. 
Published: October 2006

Abstract—At various times during a 2‐day study, the levels of adenine nucleotides and selected glycolytic intermediates were determined in brains of chicks fed a diet containing d‐galactose (40%, w/w). The levels of ATP and glucose 6‐phosphate had decreased by 9 h after initiation of the diet, whereas those of fructose 1,6‐diphosphate, 3‐phosphoglycerate, l‐α‐glycerophosphate, and lactate were not reduced until after 18 h had elasped. Although glucose 1‐phosphate was not appreciably affected, glucose and glycogen were depleted during the latter stages of the toxicity. The cerebral levels of 3′,5′‐cyclic AMP and citrate did not differ significantly between the two dietary groups at 48 h. The changes in the levels of cerebral glycolytic intermediates and high‐energy phosphates during ischemia indicated that the glycolytic rate was diminished in the chicks fed galactose and that high‐energy phosphate compounds were depleted sooner than in controls. After intraperitoneal injection of [14C]glucose, the specific radioactivity and levels of glucose in the plasma from chicks fed either diet were similar, whereas they were significantly reduced in the brains from galactosefed animals. We suggest that galactose interferes with the uptake of glucose into the brain and that this mechanism may be an important factor in d‐galactose‐induced neurotoxicity in the chick.
ENZYMIC SYNTHESIS OF PSYCHOSINE SULPHATE
Authors: Nussbaum J.‐L. , Mandel P. 
Published: October 2006

Abstract—An enzyme which catalyses the synthesis of psychosine sulphate by the transfer of [35S]sulphate from 3′‐phosphoadenosine 5′‐phosphosulphate to galactosyl‐sphingosine has been demonstrated in the brain of the young mouse. The enzyme activity appears to be bound to a microsomal fraction which is spun down with the synaptosomes. The product of the incubation mixture has been characterized as psychosine sulphate by a variety of TLC separations and other chemical procedures. Several parameters (detergent, cations, substrate and 3′‐phosphoadenosine 5′‐phosphosulphate concentrations, pH and incubation time), affecting the 3′‐phosphoadenosine 5′‐phosphosulphate‐psychosine sulphotrans‐ferase activity, have also been investigated. In the normal mouse brain there is a maximum enzyme activity at 17–19 days after birth, which is the period of most rapid myelin formation. In the brains of Jimpy mice, mutants with myelin deficiency, the activity is reduced and reaches a maximum around the 13th day. The lower activity correlates with the small amounts of sulphatides in Jimpy mouse brains. The results are discussed and related to present knowledge of galactolipid biosynthesis.
SOME PHYSICAL PROPERTIES OF BOVINE ADRENAL MEDULLARY DOPAMINE β‐HYDROXYLASE
Authors: Foldes A. , Jeffrey P. L. , Preston B. N. , Austin L. 
Published: October 2006

Abstract(1) Dopamine, β‐hydroxylase (EC 1.14.2.1) was purified from bovine adrenal medullae according to the method of Foldes, Jeffrey, Preston and Austin (1972).(2) The kinetics, pH optimum and the effect of Cu2+ ions on the purified enzyme were found to resemble those of the enzyme isolated by more involved procedures.(3) The sedimentation coefficient (s20) of the homogeneous enzyme in 10 mM‐phosphate buffer, pH 7·2, containing 0·1 M‐NaCI was found to be 10·24 ± 0·12 (S.E.M. of 10 determinations).(4) The effect of pH on the mol. wt. of the enzyme was investigated and no large deviation was found from the native mol. wt. of 290,000 in the pH range 3·9 to 11·1.(5) The amino acid analysis of dopamine β‐hydroxylase is presented, and is contrasted to that of chromogranin A purified from the same chromaffin granule lysate.(6) Treatment with either 8 M‐urea or 0·1% (w/v) sodium dodecyl sulphate was found to dissociate the enzyme into three similar, non‐active subunits, each of mol. wt. of the order of 100,000.
THE CONTRIBUTION OF AXOPLASMIC FLOW IN OPTIC NERVE AND PROTEIN SYNTHESIS WITHIN THE OPTIC TECTUM TO SYNAPTIC MEMBRANE PROTEINS OF THE CHICK OPTIC TECTUM1
Authors: Carton H. C. , Appel S. H. 
Published: October 2006

AbstractIn the 5‐day‐old chick, radioactive leucine was incorporated into proteins of synaptosomal and subsynaptosomal fractions both by fast axoplasmic flow and synthesis within the optic tectum. The distribution of radioactivity in subsynaptosomal fractions suggested that both pathways contribute to the protein constituents of each fraction. The relative contributions to each fraction were similar except for the supernatant proteins, for which fast axoplasmic flow contributed less than the synthesis within the optic tectum. The qualitative contribution of fast flow and synthesis within the optic tectum to the synaptic membrane fraction was distinctive. Fast axoplasmic flow preferentially labelled the high molecular weight proteins, whereas synthesis within the optic tectum labelled a larger percentage of smaller molecular weight proteins.