bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE EFFECT OF INTRAHIPPOCAMPAL KAINIC ACID INJECTIONS AND SURGICAL LESIONS ON NEUROTRANSMITTERS IN HIPPOCAMPUS AND SEPTUM
Authors: Fonnum F. , Walaas I. 
Published: October 2006

AbstractLocal injection of kainic acid (2 μg) was accompanied by destruction of intrinsic neurons in the dorsal part of hippocampus. The lesion was accompanied by a 75% reduction in glutamate decarboxylase activity, a 60% reduction in the high affinity uptake of l‐glutamate, a 40‐60% reduction in the endogeneous levels of aspartate, glutamate and GABA and no changes in the activities of choline acetyltransferase or aromatic amino acid decarboxylase in the dorsal hippocampus. Unilateral destruction of neurons in the dorsal hippocampus was followed by a 20‐40% reduction in the high affinity uptake of glutamate in lateral, but not in medial septum, on both sides. There was no reduction in choline acetyltransferase, glutamate decarboxylase or aromatic amino acid decarboxylase activities in the lateral or medial part of the septum. Transection of fimbria and superior fornix was accompanied by a severe reduction in choline acetyltransferase and aromatic amino acid decarboxylase activity in hippocampus, in the high affinity uptake of glutamate and in the endogenous level of glutamate in the lateral septum. The results are consistent with the concept that in the hippocampus kainic acid destroys intrinsic neurons and not afferent fibres. It seems therefore that all GABAergic fibres in the hippocampus belong to intrinsic neurons whereas glutamergic and aspartergic neurons belong partly to local neurons. The connection from the hippocampus to the lateral septum probably uses glutamate as a transmitter.
IRREVERSIBLE ZINC ION INHIBITION OF (Na+‐K+)‐ADENOSINETRIPHOSPHATASE, Na+‐PHOSPHORYLATION, AND K + ‐p‐NITROPHENYLPHOSPHATASE OF ELECTROPHORUS ELECTRICUS ELECTROPLAX1
Authors: Gettelfinger Dennis M. , Siegel George J. 
Published: October 2006

AbstractZinc ion in micromolar concentrations is an irreversible inhibitor of Electrophorus electricus electroplax microsomal (Na+‐K+)‐ATPase. The rate of inhibition is dependent on [ZnCl2] and the extent of inhibition varies with the ratio of ZnCl2 to microsomal protein. The same kinetics are observed for inhibition of K+ ‐p‐nitrophenylphosphatase and steady‐state levels of Na+ ‐dependent enzyme phosphorylation. The observations suggest that a Zn2+ ‐sensitive conformational restraint is important to both kinase and phosphatase activities. The fact that inhibition is irreversible has implications for models seeking to relate zinc effects in tissue to inhibition of (Na+‐K+)‐ATPase.
A COMPARISON BETWEEN FLUOROMETRIC AND MASS FRAGMENTOGRAPHIC DETERMINATIONS OF HOMOVANILLIC ACID AND 5‐HYDROXYINDOLEACETIC ACID IN HUMAN CEREBROSPINAL FLUID
Authors: Sjöquist Birgitta , Johansson Barbro 
Published: October 2006

Abstract—HVA and 5‐HIAA in human cerebrospinal fluid were quantitatively determined by both fluorometry and mass fragmentography. The homovanillic acid values obtained by fluorometry were significantly lower than those obtained by mass fragmentography (P < 0.05). The correlation coefficient between values for HVA obtained by the two methods was high, r= 0.90. For 5‐HIAA the concentrations obtained by the two methods were not significantly different while the correlation coefficient was lower, r= 0.55.
MULTIPLE FORMS OF CHOLINE ACETYLTRANSFERASE AND THE HIGH AFFINITY UPTAKE OF CHOLINE IN BRAIN OF DEVELOPING AND ADULT RATS
Authors: Atterwill C. K. , Prince A. K. 
Published: October 2006

Abstract—The multiple molecular forms of choline acetyltransferase (ChAT) were analysed during the postnatal development of rat brain. Changes in the sodium‐dependent, high affinity uptake of [3H]choline (HAUC) and in the efficiency of conversion of labelled choline into ACh in vitro were also examined. Both mature and 7‐day old brain contained three molecular forms of ChAT, with isoelectric points of pH 7.3, 7.9 and 8.3, but the immature brain appeared to contain smaller concentrations of the most basic form of the enzyme (pI = 8.3). Of the total choline uptake measured in slices of frontal cortex, adult samples exhibited a greater proportion of HAUC than 7‐day samples and appeared to acetylate more efficiently the [3H]choline accumulated by high affinity uptake. This evidence suggests a basic molecular form of ChAT, appearing in rat brain during postnatal development, might be responsible for the efficient coupling of the high affinity uptake and subsequent acetylation of choline in cholinergic nerve terminals.
REGIONAL BRAIN LEVELS OF γ‐HYDROXYBUTYRATE IN HUNTINGTON'S DISEASE
Authors: Ando N. , Gold B. I. , Bird E. D. , ROTH R. H. 
Published: October 2006

Abstract—A highly sensitive electron capture gas chromatographic method was developed for quantitation of γ‐hydroxybutyrate (GHB) in tissue. This method involves an improved, extraction and purification procedure and a one‐step derivatization of GHB to the methyl ester‐O‐heptafluorobutyrate. As low as 5 ng of GHB in tissue was accurately quantitated by this method.By means of this improved method, endogenous levels of GHB in several regions of brains obtained post‐mortem from patients with Huntington's disease were determined, and compared with brain samples obtained post‐mortem from non‐neurological controls. The levels of GHB found in the caudate and substantia nigra obtained from Huntington's patients were significantly higher than the GHB levels found in similar regions of brain obtained from a non‐neurological control group. The content of GABA in the same choreic and control brain samples was also determined. No significant correlation between changes in GHB and GABA levels was observed although there was a trend towards an inverse relationship. The high level of GHR in Huntington's disease may be related to the decrease in succinate:oxidoreductase (EC 1.3.99.1) activity reported by Stahl & Swanson (1974).In two subjects (one control and one Huntington patient) the zonal distribution of GHB in substantia nigra was also determined. The zona reticulata from choreic brain contained a substantially higher level of GHB, whereas the zona compacta contained an amount similar to the level found in control brain.
PROTEOLIPID PROTEIN: SYNTHESIS AND ASSEMBLY INTO QUAKING MOUSE MYELIN
Authors: Greenfield S. , Williams N. I. , White M. , Brostoff S. W. , Hogan E. L. 
Published: October 2006

AbstractThe incorporation of radioactive glycine into the major myelin proteolipid protein isolated from whole brain and from purified myelin of Quaking mice and normal littermates was compared. In a typical experiment, four Quaking mice and four littermate controls were injected intracranially with 250 μCi [2‐3H]glycine and 25 μCi [U‐14C]glycine respectively. Three hours later, the eight mice were killed and their brains combined. Equivalent portions were taken for (1) chloroform‐methanol (2:1) extraction followed by ether precipitation of proteolipid from the brain and (2) myelin preparation. The 3H/14C ratios for the microsomes:, the major myelin proteolipid as well as the other non‐myelin proteolipids extracted from whole brain was approx 3.0. while the 3H/14C ratio for proteolipid protein in myelin was near 0.4. These findings were consistent for ages studied between 18 and 90 days. The results indicate that the synthesis of the major myelin proteolipid protein in the whole brain of Quaking mouse, as seen previously in our studies on basic protein, proceeds at a normal rate relative to microsomes but its incorporation into myelin is depressed. A working hypothesis of myelin membrane assembly is presented to account for the defect in the incorporation of these proteins into Quaking myelin.
HETEROGENEITY OF HISTAMINE Hi‐RECEPTORS: SPECIES VARIATIONS IN [3H]MEPYRAMINE BINDING OF BRAIN MEMBRANES
Authors: Chang Raymond S. L. , Tran Vinh Tan , Snyder Solomon H. 
Published: October 2006

Abstract[3H]Mepyramine binds with high affinity to membranes from brain of human, rat, guinea‐pig, rabbit and mouse with drug specificity indicating an association with histamine H1receptors. Considerable species differences occur in the affinity of [3H]mepyramine, with guinea‐pig and human having 34 times greater affinity than rat, mouse or rabbit. The greater affinity of [3H]mepyramine in guinea‐pig than in rat is attributable both to faster association and slower dissociation rates in guinea‐pig. Species differences in affinity for H1 receptor sites occur for some antihistamines but not for others. Some tricyclic antidepressant and neuroleptic drugs are extremely potent inhibitors of [3H]mepyramine binding, exceeding in potency any H1 antihistamines examined. The tricyclic antidepressant doxepin and the neuroleptic clozapine are the most potent of all drugs examined in competing for [3H]mepyramine binding. The regional distribution of specific [3H]mepyramine binding differs considerably in the various species examined.
THE EFFECTS OF CHRONIC REGIMENS OF CLORGYLINE AND PARGYLINE ON MONOAMINE METABOLISM IN THE RAT BRAIN
Authors: Campbell I. C. , Robinson D. S. , Lovenberg W. , Murphy D. L. 
Published: October 2006

AbstractThe effects of chronic administration of clorgyline and pargyline on rat brain monoamine metabolism have been examined. The inhibitory selectivity of these drugs towards serotonin deamina‐tion (MAO type A) and phenylethylamine deamination (MAO type B) can be maintained over a 21‐day period by proper selection of low doses of these drugs (0.5‐1.0 mg/kg/24h). The results are consistent with MAO type A catalyzing the deamination of serotonin and norepinephrine and with MAO type B having little effect on these monoamines. Dopamine appears to be dcaminated in vivo principally by MAO type A. Clorgyline administration during a 3‐week period was accompanied by persistent elevations in brain norepinephrine concentrations; serotonin levels were also increased during the first 2 weeks, but returned towards control levels by the third week of treatment. Low doses of pargyline did not increase brain monoamine concentrations, but treatment with higher doses for 3 weeks led to elevations in brain norepinephrine and 5‐hydroxytryptamine; at this time significant MAO‐A inhibition had developed. The changes in monoamine metabolism seen at the end of the chronic clorgyline regimen are not due to alterations in tryptophan hydroxylase activity. At this time tyrosine hydroxylase activity was also unaffected.
EXPERIMENTAL ALLERGIC ENCEPHALOMYELITIS: SEQUESTERED ENCEPHALITOGENIC DETERMINANT IN THE BOVINE MYELIN BASIC PROTEIN12
Authors: Hashim G. A. , Sharpe R. D. , Carvalho E. F. 
Published: October 2006

AbstractThe presence of a sequestered encephalitogenic determinant for Lewis rats in the bovine myelin BP was demonstrated with synthetic peptide sequences prepared in our laboratory by the Merrifield solidphase method. The sequence of the encephalitogenic determinant (residues 75‐84) from bovine BP (peptide S6), H‐Ala‐Gln‐Gly‐His‐Arg‐Pro‐Gln‐Asp‐Glu‐Asn‐OH, is similar but not identical to the sequence reported for the guinea pig BP (peptide S53), H‐Ser‐Gln‐(–)‐(–)‐Arg‐Ser‐Gln‐Asp‐Glu‐Asn‐OH. The presence or the absence of Gly‐His from the sequence of either the bovine or the guinea‐pig determinants did not alter their encephalitogenic potencies; however, the presence of Gly‐His at positions 77 and 78 together with H‐Gly‐Ser‐Leu‐Pro‐Gln‐Lys‐ (residues 69‐74) at the N‐terminal end of the bovine determinant destroyed its encephalitogenic potency.In contrast to the absence of Gly‐His from the potent encephalitogenic guinea‐pig BP, guinea‐pig fragment 44‐89, and synthetic peptide S49, its presence in the bovine sequence prevents recognition of this determinant and renders the parent bovine BP, bovine fragment 44‐89, and synthetic peptide S8 (residues 69‐84) relatively non‐encephalitogenic. The results of this study suggest that intramolecular interactions occur between adjacent amino acids, conferring secondary or tertiary structures upon this region of the bovine BP which renders the encephalitogenic determinant inaccessible for recognition by the host animal. The presence of sequestered disease‐inducing determinants needs to be considered in choosing a particular BP for therapeutic use.
EFFECTS OF LITHIUM TREATMENT IN VITRO AND IN VIVO ON ACETYLCHOLINE METABOLISM IN RAT BRAIN
Authors: Jope Richard S. 
Published: October 2006

Abstract— The effects of LiCl on cholinergic function in rat brain in vitro and in vivo have been investigated. The high affinity transport of choline and the synthesis of acetylcholine in synaptosomes were reduced when part (25‐75%) of the NaCl in the buffer was replaced with LiCl or sucrose. This appeared to be due to lack of Na+ rather than to Li+, as addition of LiCl to normal buffer had little effect.Following an injection of LiCl (10mmol/kg, i.p.) into rats the concentration of a pulsed dose of [2H4]choline (20 μmol/kg, i.v., 1 min) and its conversion to [2H4]acetylcholine, and the concentrations of [2H2]acetylcholine and [2H0]choline were measured in the striatum, cortex, hippocampus and cerebellum. The [2H4]choline and [2H4]acetylcholine were initially (15 min after LiCl) reduced (to −30% in the cortex) and later (24 h after LiCl) increased (to + 50% in the striatum). There was a corresponding initial increase (to +50% in the cerebellum) and later decrease (to −30% in the hippocampus) of the endogenous acetylcholine and choline. These results indicate an initial decrease and later increase in the utilization of acetylcholine after acute treatment with LiCl.Following 10 days of treatment with LiCl there was an increased rate of synthesis of [2H4]acetylcholine from pulsed [2H4]choline in the striatum, hippocampus and cortex (P < 0.05). The high affinity transport of [2H4]choline and its conversion to [2H4]acetylcholine was activated (131% of control; P < 0.01) in synaptosomes isolated from brains of 10‐day treated rats. Investigation of synaptosomes isolated from striatum, hippocampus and cortex revealed that only striatal [2H4]acetylcholine synthesis was significantly stimulated. Kinetic analysis demonstrated that the apparent KT for choline was decreased by 30% in striatal synaptosomes isolated from rats treated for 10 days with LiCl. Striatal synaptosomes from 10‐day treated rats compared to striatal synaptosomes from untreated rats also released acetylcholine at a stimulated rate in a medium containing 35 mM‐KCl. These results indicate that LiCl treatment stimulates cholinergic activity in certain brain regions and this may play a significant role in the therapeutic effect of LiCl in neuropsychiatric disorders.
[1251]2α‐BUNGAROTOXIN AND [3H]QUINUCLIDINYLBENZILATE BINDING IN CENTRAL NERVOUS SYSTEMS OF DIFFERENT SPECIES
Authors: Salvaterra Paul M. , Foders Renée M. 
Published: October 2006

Abstract— [125I]Diiodo α‐bungarotoxin ([125I]2BuTx) and [3H]quinuclidinylbenzilate ([3H]QNB) binding sites were measured in post‐nuclear membrane fractions prepared from whole brains or brain regions of several species. Species studied included Drosophila melanogaster (fruit fly), Torpedo californiea (electric ray), Carassius auratus (goldfish), Ram pipiens (grass frog), Kana cutesheiana (bullfrog), Rattus norvegicus (rat, Sprague‐Dawley), Mus muscalus (mouse, Swiss random, C58/J, LG/J), Oryctolagus cuniculus (rabbit, New Zealand Whitc), and Bos (cow). Acetyl‐CoA: choline O‐acetyltransferase (EC 2.3.1.6) levels were also determined in the post nuclear supernatants and correlated with the number of binding sites.All species and regions except Drosophila had 16–150 fold more [3H]QNB binding sites than [125I]2BuTx binding sites. Brain regions with the highest levels of [125I]2BuTx binding were Drosophila heads (300 fmol/mg), goldfish optic tectum (80fmol/mg), and rat and mouse hippocampus (3040 fmol/mg). The highest levels of [3H]QNB binding were seen in rat and mouse caudate (1.3–1.6 pmol/mg). Lowest levels of [3H]QNB and [125I]2BuTx binding were seen in cerebellum. The utility of [125I]2BuTx and [3H]QNB binding as quantitative measures of nicotinic and muscarinic acetylcholine receptors in CNS is discussed.
MASS FRAGMENTOGRAPHY OF PHENYLETHYLAMINE, m‐ AND p‐TYRAMINE AND RELATED AMINES IN PLASMA, CEREBROSPINAL FLUID, URINE, AND BRAIN
Authors: Karoum F. , Nasrallah H. , Potkin S. , Chuang L. , Moyer‐Schwing J. , Phillips I. , Wyatt R. J. 
Published: October 2006

Abstract—A mass fragmentographic method for the assay of phenylethylamine (PEA) and a number of related amines in several biological materials is described. The gas chromatographic column employed for this analysis is a 12ft 1/8 in. o.d. steel column packed with 0.5% OV22+ 2% SE54 + 1% OV210 coated on 80/100 mesh chromosorb W (HP). The mass spectral characteristics of these amines are illustrated, compared, and discussed.Of the various monoamines which could be measured, only PEA, m‐ and p‐tyramine were detected in measurable quantities. Phenylethanolamine and p‐octopamine were found in trace amounts in urine, plasma, cerebrosponal fluid, and rat brain. No diurnal variation in the urinary excretion of PEA, m‐ and p‐tyramine was observed. Plasma concentration of PEA or p‐tyramine did not significantly change 1 h after eating a breakfast. Furthermore, consuming 200 g of Cadbury milk chocolate containing about 1 mg of PEA, 0.1 mg of phenylethanolamine and 10 mg of p‐tyramine did not significantly alter urine excretions of these three amines.In the brain, as has been reported by others, we found that PEA and p‐tyramine are not evenly distributed and that the highest concentrations are found in the hypothalamus and caudate.From the results obtained we concluded that PEA, m‐ and p‐tyramine are probably produced from endogenous sources and that the direct contribution of diet to their urine excretion is small.
Dissociation of Myelin from its‘Enzyme Markers’During Ontogeny
Authors: Waehneldt T. V. , Lane J. D. 
Published: October 2006

Abstract: To avoid any loss of membranes, total particulate material prepared from the forebrain and spinal cord of rats of different ages was fractionated on linear sucrose gradients. Particle distribution, proteins and enzyme activities were measured. Beginning at early ages, optical density increases were observed around 0.60 m‐sucrose, which corresponded to myelin deposition, and were expressed by the appearance of typical myelin proteins, which paralleled the peak activity of myelin‐associated enzymes. During later development myelin proteins were found over a broad density range together with optical density shifts to higher (forebrain) and lower (spinal cord) values. In both regions myelin‐associated enzymes shifted to heavier densities and were dissociated from the density region commonly considered to be compacted myelin.
Stability of Bovine Adrenal Medulla Cells in Culture
Authors: Kilpatrick Daniel L. , Ledbetter Freeman H. , Carson Keith A. , Kirshner Annette G. , Slepetis Ruta , Kirshner Norman 
Published: October 2006

Abstract: The functional stability of primary cultures of adrenal medulla cells was investigated. Isolated cells were prepared by treatment of bovine adrenal glands with collagenase followed by purification on Percoll density gradients and were maintained in Dulbecco's medium containing 10% fetal calf serum. Within 12 h after plating on plastic culture dishes, the cells became firmly attached and exhibited good survival for periods of time up to 3 weeks, as indicated by their morphology using light and electron microscopy, by maintenance of their content of catecholamines, tyrosine hydroxylase, dopamine‐β‐hydroxylase, and phenylethanolamine N‐methyltransferase, and their ability to respond to secretagogues. During the first 10 days to 2 weeks in culture there was little or no change in any of these parameters. During the 3rd week there were progressive losses of catecholamine and enzyme activities and increased vacuolization of medullary cells. The cells synthesized protein and RNA with no apparent loss in activities over the period studied, but did not incorporate [3H]thymidine into PCA‐precipitable material. The cells responded to secretagogues and secretory antagonists similarly to isolated perfused adrenal glands. The studies described here demonstrate that primary cultures of adrenal medulla cells provide an excellent experimental system for obtaining more detailed information on stimulus‐secretion coupling and other functional aspects of the adrenal medulla.
Phylogenetic Distribution of Neuron‐Specific Enolase
Authors: Clark‐Rosenberg R. L. , Marangos P. J. 
Published: October 2006

Abstract: Neurons and neuroendocrine cells contain a unique isoenzyme of the glycolytic enzyme enolase which is not found in other cells. This acidic enolase isoenzyme has been designated neuron specific enolase or NSE and is easily identified by its elution on DEAE sephadex. The present study shows that brain tissue from species such as yeast, fish and frog do not contain appreciable amounts of acidic “NSE‐like” enolase suggesting that lower species do not have this neuronal isoenzyme.
Studies on the Linkage of Energy Metabolism and Neuronal Activity in the Isolated Perfused Rat Brain
Authors: Dirks B. , Hanke J. , Krieglstein J. , Stock R. , Wickop G. 
Published: October 2006

AbstractAn isolated rat brain preparation was perfused using glucose‐free (=aglycemic) media. The high‐energy phosphates, substrates of the glycolytic pathway, free atnino acids, acetylcholine as well as the intracellular distribution of hexokinase activity were determined in brain tissues. The EEG was evaluated visually. The levels of glycolytic substrates, glutamate, and glutamine in cortical tissue decreased after aglycemic perfusion, whereas the aspartate level increased and the GABA level remained unchanged. The high‐energy phosphate content seemed to be unaffected for about 15 min of aglycemic perfusion and fell significantly after 20 min. The EEG of the isolated brain changed rapidly after starting aglycemic perfusion and became isoelectric after 12–15 min. Hyperglycemic perfusion (35 mmol glucose per liter perfusion medium) did not alter the energy metabolism of the isolated brain. The breakdown of cerebral energy metabolism and of EEG activity was postponed when thiopental was added to the perfusion medium. The soluble hexokinase activity measured in cortical tissue was reduced after aglycemic perfusion and was enhanced after thiopental. Hyperglycemic perfusion did not influence the intracellular hexokinase distribution. The acetylcholine level in the striatum of the isolated rat brain was significantly decreased by aglycemia and was increased in hypothalamus by thiopental. It was suggested that hexokinase bound to the mitochondrial membrane may play an important role in the relationship of energy metabolism and neuronal activity.