bluuebunny/crossref_metadata_2025_split huggingface dataset:
PROPERTIES OF TYROSINE HYDROXYLASE IN PERIPHERAL NERVES
Authors: Numata (Sudo) Y. , Nagatsu T. 
Published: October 2006

Abstract—Approximately 80 per cent of tyrosine hydroxylase activity in bovine mandibular nerve and rabbit sciatic nerve was soluble, and the rest of the activity was particle‐bound. The soluble enzyme in bovine mandibular nerve was isolated by ammonium sulphate fractionation (25–35 per cent saturation). The enzyme had a pH optimum at 5·9 in Tris‐acetate buffer, and at 6·5 in Tris‐HCl or phosphate buffer. The enzyme required a tetrahydropteridine cofactor. Km values toward various tetrahydropteridines such as l‐erythro‐tetrahydrobiopterin (a probable natural cofactor), 2‐amino‐4‐hydroxy‐6‐methyltetrahydropteridine, and 2‐amino‐4‐hydroxy‐6,7‐dimethyltetrahydropteridine were 2 × 10−5m, 5 × 10−5m and 4 × 10−4m, respectively. The Km value for tyrosine at 1 × 10−3m‐2‐amino‐4‐hydroxy‐6‐methyltetrahydropteridine as a cofactor was 5 × 10−5m. The enzyme activity was markedly stimulated with Fe2+ or catalase, but Fe2+ gave higher activity. The activity was inhibited with α, α′‐dipyridyl, l‐α‐methyl‐p‐tyrosine, and various catecholamines. Among catecholamines, dopamine was the most potent inhibitor. l‐5‐Hydroxytryptophan was an inhibitor as potent as dopamine. Neither d‐5‐hydroxytryptophan nor 5‐hydroxytryptamine inhibited the enzyme. The inhibition by l‐5‐hydroxytryptophan was partially competitive with tetrahydrobiopterin at concentrations higher than 9 × 10−5m, and partially uncompetitive at concentrations lower than 9 × 10−5m. The addition of heparin or lysolecithin did not affect enzyme activity with tetrahydrobiopterin as cofactor.
BRAIN LIPID COMPOSITION OF IMMATURE THIAMINE‐DEFICIENT AND UNDERNOURISHED RATS1
Authors: Geel S. E. , Dreyfus P. M. 
Published: October 2006

Abstract—The brain lipid composition of 25‐day‐old offspring of rats exposed to dietary thiamine (vitamin B1) deficiency from the 14th day of gestation was examined and compared to normal and pair‐fed (undernourished) controls. Thiamine‐deprived rats displayed neurological signs and a marked diminution of growth at 25 days of age. No changes in brain lipids of either whole brain or selected brain areas (brain stem, cerebellum, diencephalon) which were distinct from the effects of undernutrition (pair‐fed controls) were observed in the thiamine‐deficient group. Undernutrition, as exemplified by the pair‐fed control group produced a highly significant depression of all lipids expressed per total brain and a significant deficit of whole brain and regional lipid, cerebroside and cholesterol concentrations indicating a deficiency in myelinogenesis. Ganglioside NeuNAc concentration was shown to be significantly greater in whole brain and certain brain areas of the same group while no changes were evident in total phospholipid concentration and the distribution of individual phospholipids. The implications of these findings in terms of the pathophysiology of thiamine‐deficiency encephalopathy and undernutrition in early life are discussed.
PURIFICATION AND PROPERTIES OF ARYLSULPHATASE FROM THE BRAIN OF THE SILKWORM BOMBYX MORI
Authors: Farooqui A. A. , Yusufi A. N. K. 
Published: October 2006

Abstract—(1)Arylsulphatase of the silkworm Bombyx mori was partially purified using ammonium sulphate fractionation, ethanol precipitation, Sephadex G–200 gel filtration and Con‐A Sepharose chromatography.(2)The purified enzyme preparation was not homogeneous but showed no β‐glucuronidase or β‐galactosidase activities.(3)The kinetic properties of the enzyme indicated that it could be classified under type‐2 arylsulpha‐tases of vertebrates.(4)The purified enzyme shows very little activity towards p‐nitrophenyl sulphate and none towards cerebroside 3‐sulphate
EFFECTS OF DOPAMINERGIC AGONISTS AND ELECTRICAL STIMULATION OF THE MIDBRAIN RAPHÉ ON THE RELEASE OF 5‐HYDROXYTRYPTAMINE FROM THE CAT BRAIN IN VIVO
Authors: Chiueh C. C. , Moore K. E. 
Published: October 2006

Abstract—The cerebroventricular system of spinal‐sectioned cats was perfused with artificial cerebrospinal fluid after the intraventricular administration of [3H]tryptophan, and the perfusate was analyzed for [3H]5‐HT. At the end of the experiment the relative contents of [3H]5‐HT in regions lining the cerebroventricular system (caudate nucleus, septum, hypothalamus) were essentially the same as the endogenous 5‐HT contents. Electrical stimulation of the midbrain raphé did not alter the efflux of total radioactivity but significantly increased the efflux of [3H]5‐HT. The addition of potassium to the perfusing CSF also increased the efflux of [3H]5‐HT, while additions of d‐amphetamine, apomorphine or l‐DOPA were without effect.
ATYPICAL INCORPORATION OF SINGLE AMINO ACIDS INTO MYELIN PROTEINS1
Authors: Johnson J. D. , King Neva L. , Binkley F. 
Published: October 2006

Abstract—Purified myelin incorporated l‐[14C]leucine and l‐[14C]lysine into myelin proteins in an enzymatic process similar to that of renal brush border membranes. The system was not inhibited by cycloheximide or puromycin or by pretreatment with ribonuclease; the reaction was inhibited by cetophenicol. ATP was an effector, shifting the optimal pH from 7.2 to 8.3. In the presence of ATP, myelin was less dense in a sucrose gradient. Ammonia was released from the membrane during the incorporation of amino acids. Myelin preloaded with cold leucine did not incorporate [14C]leucine but did incorporate [14C]lysine; there was no cross inhibition between the two amino acids. The incorporation was into or onto proteins of the Wolfgram proteolipid fraction of myelin. The incorporation was of the high affinity type with a Km of 10−7m and was restricted to the natural amino acids.
EVOLUTION DE L'INCORPORATION IN VIVO DE L'ACIDE [14C]OROTIQUE DANS L'ARN ET L'ADN DU CERVELET DE JEUNES RATS HYPO‐ ET HYPERTHYROIDIENS: EFFETS COMPARATIFS DE L'HYPO‐ ET L'HYPERTHYROIDIE SUR LES MULTIPLICATIONS CELLULAIRES
Authors: Dainat J. , Rebière A. 
Published: October 2006

Résumé—L'evolution du poids du corps et du cervelet, de la quantité d'ARN, d'ADN et des protéines du cervelet. est étudiée jour aprés jour durant les 10 premiers jours de la vie postnatale et à 12, 14 et 17 jours chez des rats normaux, hypo‐ et hyperthyroïdiens.Chez les animaux normaux: (1) Le contenu moyen des cellules en protéines diminue de 1 à 2 jours, augmente ensuitc jusqu'à un maximum à 4 jours, puis decroit réguliérement. (2) La RAS de I'ARN varie fortement de la naissance à 9 jours, et présente deux maxima à 4 et 6 jours. Aprhs 9 jours elle déroît fortement. (3) L'activite mitotique (nombre de cellules en phase de réplication) croït, passe par un maximum à 9 jours, puis décroït. (4) La RAS de I'ADN (pourcentage de la population cellulaire en phase de réplication) passe par un maximum à 6 jours. (5) Le rendement mitotique (nombre de cellules en phase de réplication rapportéà une même activité mitotique) dácroît irréguliirèment de 2 à 7 jours, puis augmente à nouveau.Chez les animaux hypothyroïdiens: (1) Le contenu moyen des cellules en protéines, augrnente de 1 a 2 jours puis décroït rtgulièrement. (2) La RAS de I'ARN, significativement supérieure à la normale, varie fortement de la naissance à 9 jours et présente deux maxima à 4 et 6 jours; après 9 jours elle décroït fortement. (3) L'activité mitotique significativement inférieure à la normale, croït dépuis la naissance, passe par un maximum à 9 jours puis décroît. (4) La RAS de L'ADN non significativement diffèrente de la normale, passe par un maximum à 6 jours, puis décroît. (5) Le rendement mitotique n'est pas significativement différent de la normale.Chez les animaux hyperthyroidïens: (1) Le contenu moyen des cellules en protkines, est maximum a 2 jours, puis decroit. (2) La RAS de I'ARN significativement inférieure à la normale, décroît depuis la naissance. (3) L'activite mitotique non significativement differente de la normale, croît depuis la naissance jusquèa un maximum à 6 jours, puis décroît. (4) La RAS de I'ADN significativement inférieure à la normale, augmente depuis la naissance jusqu'à 5 jours, puis decroît. (5) Le rendement mitotique est signiticativement superieur a la normale.Dans les 3 groupes d'animaux. le maximum des divisions cellulaires est toujours précédé par une augmentation dc la taille moycnne des cellules. Chez les animaux hypothyroïdiens, le taux des morts cellulaires est supérieur à la normale et la taille moyenne des cellules l'est également durant les 14 premiers jours de la vie postnatale. Chez les animaux hyperthyroîdiens, le taux des morts cellulaires est inférieur à la normale et la taille moyenne des cellules est superieure à 14 et 17 jours.
UPTAKE AND RELEASE OF D‐ AND L‐ASPARTATE BY RAT BRAIN SLICES
Authors: Davies L. P. , Johnston G. A. R. 
Published: October 2006

Abstract—D‐Aspartate is accumulated by slices of adult rat cortex by a high affinity uptake which is abolished if the sodium ions in the incubation medium are replaced by choline. A small uptake of D‐aspartate takes place if the sodium ions are replaced by lithium ions. It appears likely that D‐aspartate shares the same transport system with L‐aspartate, and that the uptake of D‐aspartate is into the same osmotically‐sensitive particles as those which accumulate L‐aspartate. D‐Aspartate is released from cerebral cortex slices by raised potassium concentrations, provided calcium is present in the perfusing buffer.Both D‐ and L‐aspartate produce gross hyperactivity when injected intraperitoneally into immature rats.Radioactive D‐aspartate may be very useful in examining the neurotransmitter role of the naturally‐ occurring L‐aspartate e.g. in studies of the autoradiographic localization of high affinity L‐aspartate accumulation, its main advantage being that, unlike L‐aspartate, D‐aspartate does not undergo rapid metabolism.
GANGLTOSIDES AND THE ARCHITECTURE OF HUMAN FRONTAL AND RAT SOMATOSENSORY ISOCORTEX
Authors: Hess Helek H. , Bass N. H. , Thalhhmer Carol , Devarakonda Rita 
Published: October 2006

AbstractGanglioside sialic acid was determined in the layers of human frontal association cortex and rat somatosensory cortex by microchemical methods of sampling and analysis. In both cortices the distribution per unit dry weight showed three main peaks or inflections: (1) at the junction of layers II and III; (2) in the lower part of layer III at the junction with IV; and (3) at the junction of layers V and VI. These distributions parallel the occurrence of high concentrations of dendritic and axonal plexuses and their synaptic articulations. In human cortex, the concentration of ganglioside sialic acid per unit dry weight was slightly greater, the amount per cell was twice as great. and the amount per neuron present was 2‐ to 6‐fold greater than in rat somatosensory cortex. The ganglioside sialic acid per cell was 120‐ to 200‐fold greater in human association cortex than in rat retina, which is a CNS region with sparse neuropil. The results support the validity of ganglioside sialic acid as an index of the relative mass of neuronal plasma membranes in neural tissues and its usefulness in chemoanatomic quantitation of axodendritic interrelationships established by synaptic contacts with local and distant neurons.
SUBSTRATE AND INHIBITOR‐RELATED CHARACTERISTICS OF MONOAMINE OXIDASE IN C6 RAT GLIAL CELLS
Authors: Murphy D. L. , Donnelly Cynthia H. , Richelson E. 
Published: October 2006

AbstractCultured C6 rat glial cells preferentially deaminated 5‐hydroxytryptamine, tryptamine, dopamine and tyramine in comparison to phenylethylamine and benzylamine. Deamination of all substrates was uniformly sensitive to inhibition by clorgyline and relatively insensitive to deprenyl. These data together with the observations of simple sigmoid curves for the inhibition of tyramine deamination by both inhibitors suggest that C6 glial cells contain mainly monoamine oxidase type A, which previously had been suggested to be primarily an intraneuronal MAO type. As these findings are in agreement with other studies of brain MA0 activity in mitochondria separated from neuronal vs glial cell preparations, they help explain why MA0 activity measured with some substrates may be little affected by lesions or by drugs producing nerve ending degeneration.
A COMPARISON OF AXONALLY TRANSPORTED PROTEINS IN THE RAT SCIATIC NERVE BY IN VITRO AND IN VIVO TECHNIQUES
Authors: THEILER R. F. , MCLURE W. O. 
Published: October 2006

Abstract—An in vitro system for studying fast axonal transport in mammalian nerves has been developed. The viability of in vitro nerve preparations was established on the basis of three criteria: electron microscopy, electrical properties, and the activities of two marker enzymes, 5'‐nucleotidase and total ATPase. The specific activity of transported proteins was greater using the in vitro procedure, and the level of locally incorporated radioactivity lower, when compared to in vivo transport experiments. Separation of solubilized transported proteins on polyacrylamide gels in the presence of sodium dodecyl sulfate showed that a large number of polypeptides are transported. Using a double label procedure which employed L‐[3H]methionine and L‐[35S]methionine, proteins transported in vitro and in vivo were compared. No differences in the electrophoretic distribution of transported proteins from the two systems was seen. The major component of transported proteins electrophoresed with an apparent molecular weight of 105,000 ± 24,000. Using the in vitro system, transported proteins were compared to those labelled locally in either Schwann cells or cells of the dorsal root ganglion. Large differences in the labelling patterns were observed in both comparisons. We conclude that in vitro procedures provide a valid means of studying rapid axoplasmic transport. The proteins carried by rapid axoplasmic transport differ from those synthesized in either the Schwann cells of the sciatic nerve or the cells of the dorsal root ganglion.
THE CHARACTERIZATION OF HISTIDINE DECARBOXYLASE AND ITS DISTRIBUTION IN NERVES, GANGLIA AND IN SINGLE NEURONAL CELL BODIES FROM THE CNS OF APLYSIA CALIFORNICA
Authors: WEINREICH D. , Yu Y.‐T. 
Published: October 2006

Abstract—Histamine (HA) is present in substantial quantities in all ganglia of Aplysia californica. Within the cerebral ganglia this amine is known to be concentrated in at least two identified neurons designated C‐2 neurons. In this study a combination of chemical and enzymatic analyses was employed to provide evidence for the existence of a biochemical pathway for HA synthesis in ganglia and individual neurons of this marine mollusk. Examination of extracts of individual neurons dissected from ganglia organ‐cultured in the presence of [3H]histidine showed that every neuron accumulated labelled histidine, but only the HA‐containing C‐2 neurons synthesized and stored labelled HA suggesting that the formation of HA in Aplysia could be catalyzed by the enzyme histidine decarboxylase (HDC). HDC activity was studied with a new microradiometric assay. Many of the properties of the molluscan HDC studied were found to correspond to the vertebrate enzyme. Enzyme activity was inhibited by α‐hydrazino‐histidine but unaffected by concentrations of α‐methyldopa or by 5‐(3,4‐dihydroxycinnamoyl) salicylic acid which produced nearly complete inhibition of aromatic amino acid decarboxylase activity. HDC was measurable in nervous but not other Aplysia tissues assayed. All 5 major ganglia contained HDC activity which spanned a 15‐fold range between the least and most active ganglia. Only 4 of the 13 nerve trunks assayed yielded measurable enzymic activity; these active nerves were associated with the cerebral ganglia which has the highest HDC activity of all measured ganglia. Of the numerous individual neurons assayed for HDC, only the C‐2 cells showed measurable enzyme activity, about 25 pmol/cell/h or 70 μmol/g protein/h. Since the activity of HDC in the HA‐containing neurons was at least three orders of magnitude larger than all other neurons assayed in the cerebral and other ganglia, these data appear to provide a direct metabolic basis for the selective presence of HA in these cells, and they indicate that the cellular presence of HDC provides a useful biochemical marker for the location of HA‐rich neurons in Aplysia.
ALTERATIONS IN ACETYLCHOLINE SYNTHESIS AND CYCLIC NUCLEOTIDES IN MILD CEREBRAL HYPOXIA
Authors: Gibson Gary E. , Shumada Masahisa , Blass John P. 
Published: October 2006

AbstractIn order to elucidate changes accompanying mild cerebral hypoxia, the synthesis of the neurotransmitter acetylcholine and the concentrations of cyclic AMP and cyclic GMP have been compared to changes in brain lactate in the forebrain of mice made mildly hypoxic. Both histotoxic hypoxia (injection of KCN) and anemic hypoxia (injection of NaNO2) were studied. Acetylcholine synthesis was followed by a double‐label technique using [U‐14C] glucose and [2H4] choline.A 43%, decrease in the synthesis of acetylcholine from [U‐14C]glucose and an 80% increase of the level of cyclic GMP accompanied hypoxia so mild that there were no significant changes in cerebral lactate, or in cyclic AMP (or in AMP: Gibson & Blass, 1976b). Changes in glucose utilization do not account for the decrease in glucose incorporation into acetylcholine. Glucose utilization decreases and then increases with increasing hypoxia, whereas incorporation into acetylcholine decreased with increased hypoxia.
ACCUMULATION OF THE FOUR MYELIN BASIC PROTEINS IN MOUSE BRAIN DURING DEVELOPMENT1
Authors: Barbarese E. , Carson J. H. , Braun P. E. 
Published: October 2006

AbstractMyelin was isolated from the brains of mice 15, 20, 30, and 60 days after birth. The total amount of basic protein present in the isolated myelin was determined by radioimmunoassay. The 4 myelin basic proteins, with molecular weights of 21,500, 18,500, 17,000 and 14,000, were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and their relative amounts were determined densitometrically. The absolute amount of each of the basic proteins was calculated from its relative amount on the gel and from the total amount of myelin basic protein in the sample as determined by radioimmunoassay. The results show that between 10 and 30 days after birth each protein accumulates at a characteristic rate so that the molar ratios among the 4 basic proteins are (in descending order according to their molecular weights) 1:5:2:10 during this period. Between 30 and 60 days after birth the 14 K and 18.5 K proteins continue to accumulate at reduced rates while the 21.5 K and 17 K proteins begin to disappear from the myelin membrane; 60 days after birth the molar ratios among the 4 basic proteins are 1:10:3.5:35. These developmental patterns of accumulation are discussed in relation to the possible role of each of the 4 myelin basic proteins in myelination.
A SIMPLE METHOD FOR THE PREPARATION OF THE IMMUNOGLOBULINS TO HYDROXYINDOLE O‐METHYLTRANSFERASE
Authors: Kuwano R. , Takahashi Y. 
Published: October 2006

AbstractA simple procedure is described for the preparation of the monospecific immunoglobulins (Ig) to bovine pineal hydroxyindole O‐methyltransferase (HIOMT) (EC 2.1.1.4). We observed that anti‐serum to HIOMT was produced in rabbits which had received subcutaneous inoculations of the crude pineal extract. The monospecific Ig to HIOMT were isolated by an immunoadsorption technique in which the brain extract was coupled to the CNBr‐activated Sepharose. The purified Ig gave a single precipitin line against the pineal extract on an Ouchterlony double diffusion plate and also by immunoelectrophoresis. All other extracts tested, cerebral cortex, cerebellum, thalamus, caudate nuclei, superior coliculus, liver, adrenal gland, kidney, retina and serum did not express precipitin lines to the purified Ig. When immunochemical titration was used, the pineal HIOMT was quantitatively precipitated by the monospecific Ig.
THE EFFECT OF TRIALKYLTIN COMPOUNDS ON TUBULIN POLYMERISATION
Authors: Tan L. P. , Ng M. L. , Kumar Das V. G. 
Published: October 2006

AbstractThe effects of trialkyltin compounds on the colchicine‐binding activity and the in vitro polymerisation of rat brain tubulin have been investigated. Trialkyltins at concentrations between 10 and 100 μM inhibited the colchicine‐binding activity of purified tubulin preparations derived from rat brain. Viscometric studies have shown that the same concentrations of trialkyltins also inhibited the in vitro polymerisation of tubulin. Both the effects were found to be concentration dependent. However, trialkyltins did not interfere with the in vitro preassembled microtubules. The reasons which are believed to explain the inhibitory effects of these compounds are discussed.
THE UTILIZATION OF GLUTAMINE BY THE RETINA: AN AUTORADIOGRAPHIC AND METABOLIC STUDY
Authors: Voaden M. J. , Lake N. , Marshall J. , Morjaria B. 
Published: October 2006

AbstractThe cells able to accumulate exogenously applied [3H]glutamine in rat, cat, frog, pigeon and guinea pig retinas have been located by autoradiography, and the fate of the labelled glutamine, as regards its incorporation into aspartic, glutamic and γ‐amino‐butyric acids, followed for 60min. The results support the notion of glutamine as a precursor of transmitter amino acids in some neurones. In particular, it would appear to be a source of a relatively stable pool of GABA which may be located, with species variation, in amacrine or ganglion cells. In the pigeon retina a glutamate pool incorporates and retains a major percentage of the label, and perikarya in the middle of the inner nuclear layer of the tissue are predominantly labelled.
STUDIES ON AXOPLASMIC TRANSPORT OF INDIVIDUAL PROTEINS: 1–ACETYLCHOLINESTERASE (AChE) IN ACRYLAMIDE NEUROPATHY
Authors: Rasool C. G. , Bradley W. G. 
Published: October 2006

Abstract— The axoplasmic transport rate and distribution of acetylcholinesterase (AChe, EC 3.1.1.7) was studied in the sciatic nerves of normal rats and those with a neuropathy due to acrylamide, by measuring the accumulation of the enzyme proximal to single and double ligatures. The single ligature experiments showed that the apparent transport rate of AChE was decreased in acrylamide neuropathy. The double ligature experiments indicated that only 8.1% of AChE was mobile in normal rat sciatic nerve. The mobility of the enzyme in acrylamide‐treated rat sciatic nerves was altered to 11.8%. The absolute transport rate of AChE in normal rat sciatic nerve was 567 mm/24 h, and in acrylamide neuropathy it was decreased to 287 mm/24 h.The amount of AChE activity transported in normal rat sciatic nerve was 2.64 μmol/24 h. The rats with acrylamide neuropathy showed a decrease in the amount of AChE activity moving in the orthograde direction (2.03 μmol/24 h).The colchicine‐binding properties of tubulin protein from sciatic nerves of normal and acrylamide‐treated rats were studied. In rats with acrylamide neuropathy, a marked decrease of 75% in tubulin‐colchicine binding was observed.
EFFECT OF OXOTREMORINE ON THE APPARENT REGIONAL TURNOVER OF ACETYLCHOLINE IN MOUSE BRAIN
Authors: Nordberg Agneta 
Published: October 2006

Abstract—The effect of oxotremorine (1 mg kg‐1i.p.) on the steady state concentration of acetylcholine (ACh) and choline (Ch) and the transformation of radioactive choline ([3H]Ch) was studied in different brain regions of the mouse following death by microwave irradiation of the head. Oxotremorine significantly increased the concentration of endogenous ACh in the cortex and hippocampus and of endogenous Ch in the cortex. Pretreatment with atropine (5 mg kg‐1i.p.) prevented the increase in ACh. The biosynthesis of radioactive ACh ([3H]ACh) was decreased in all brain regions. Atropine (5 mg kg‐1) pretreatment counteracted this effect of oxotremorine (1 mg kg‐1), while methylatropine (5 mg kg‐1) had no effect except in the striatum. A calculation of the apparent turnover rate of ACh showed that oxotremorine (1 mg kg‐1) decreased the turnover in the cortex, hippocampus, midbrain. and striatum.