bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantification of Rat Cerebral Cortex Na+,K+‐ATPase: Effect of Age and Potassium Depletion
Authors: Schmidt Thomas Andersen , Larsen Jim Stenfatt , Kjeldsen Keld
Published: July 2010

Abstract:Na+,K+‐ATPase concentration in rat cerebral cortex was studied by vanadate‐facilitated [3H]ouabain binding to intact samples and by K+‐dependent 3‐O‐methylfluorescein phosphatase activity determinations in crude homogenates. Methodological errors of both methods were evaluated. [3H]Ouabain binding to cerebral cortex obtained from 12‐week‐old rats measured incubating samples in buffer containing [3H]ouabain, and ouabain at a final concentration of 1 × 10–6mol/L gave a value of 11,351 ± 177 (n = 5) pmol/g wet weight (mean ± SEM) without any significant variation between the lobes. Evaluation of affinity for ouabain was in agreement with a heterogeneous population of [3H]ouabain binding sites. K+‐dependent 3‐O‐methylfluorescein phosphatase activity in crude cerebral homogenates of age‐matched rats was 7.24 ± 0.14 (n = 5) μmol/min/g wet weight, corresponding to a Na+,K+‐ATPase concentration of 12,209 ± 236 pmol/g wet weight. It was concluded that the present methods were suitable for quantitative studies of cerebral cortex Na+,K+‐ATPase. The concentration of rat cerebral cortex Na+,K+‐ATPase showed ∼10‐fold increase within the first 4 weeks of life to reach a plateau of ∼11,000–12,000 pmol/g wet weight, indicating a larger synthesis of Na+,K+pumps than tissue mass in rat cerebral cortex during the first 4 weeks of development. K+depletion induced by K+‐deficient fodder for 2 weeks resulted in a slight tendency toward a reduction in K+content (6%,p> 0.5) and Na+,K+‐ATPase concentration (3%,p> 0.4) in cerebral cortex, whereas soleus muscle K+content and Na+,K+‐ATPase concentration were decreased by 30 (p< 0.02) and 32% (p< 0.001), respectively. Hence, during K+depletion, cerebral cortex can maintain almost normal K+homeostasis, whereas K+as well as Na+,K+pumps are lost from skeletal muscles.
Existence of Three Subtypes of Bradykinin B2Receptors in Guinea Pig
Authors: Seguin L. , Widdowson P. S. , Giesen‐Crouse E.
Published: July 2010

Abstract:We describe the binding of [3H]bradykinin to homogenates of guinea pig brain, lung, and ileum. Analysis of [3H]bradykinin binding kinetics in guinea pig brain, lung, and ileum suggests the existence of two binding sites in each tissue. The finding of two binding sites for [3H]bradykinin in ileum, lung, and brain was further supported by Scatchard analysis of equilibrium binding in each tissue. [3H]Bradykinin binds to a high‐affinity site in brain, lung, and ileum (KD= 70–200 pM), which constitutes ∼20% of the bradykinin binding, and to a second, lower‐affinity site (0.63–0.95 nM), which constitutes the remaining 80% of binding. Displacement studies with various bradykinin analogues led us to subdivide the high‐ and lower‐affinity sites in each tissue and to suggest the existence of three subtypes of B2receptors in the guinea pig, which we classify as B2a, B2b, and B2c. Binding of [3H]bradykinin is largely to a B2breceptor subtype, which constitutes the majority of binding in brain, lung, and ileum and represents the lower‐affinity site in our binding studies. Receptor subtype B2cconstitutes ∼20% of binding sites in the brain and lung and is equivalent to the high‐affinity site in brain and lung. We suggest that a third subtype of B2receptor (high‐affinity site in ileum), B2a, is found only in the ileum. All three subtypes of B2receptors display a high affinity for bradykinin, whereas they show different affinities for various bradykinin analogues displaying agonist or antagonist activities. The potency of bradykinin analogues for the three B2subtypes is as follows: for B2a, bradykinin = D‐Arg[Hyp3,Thi5,D‐Tic7,Oic8]bradykinin (HOE 140) > [Hyp3]bradykinin > kallidin = D‐Argo[Hyp3,Thi5,8,D‐Phe7]bradykinin (NPC 349) = [Thi5,8,D‐Phe7]bradykinin (NPC 431) > D‐Arg[Hyp3,D‐Phe7]bradykinin (NPC 567) = [D‐Phe7]bradykinin (NPC 361); for B2b, bradykinin = HOE 140 > kallidin > NPC 349 = [Hyp3]bradykinin > NPC 431 = NPC 567 = NPC 361; and for B2c, bradykinin > NPC 349 = NPC 431 > kallidin > [Hyp3]bradykinin > HOE 140. We thought that the binding characteristics of the bradykinin analogues in lung were not sufficiently different to warrant the classification of a separate class of receptors (B3) as has been proposed previously. We suggest that, based on the structure of the bradykinin analogues, that amino acid residues 3, 5, and 8 of the bradykinin sequence are important for the differentiation of binding at the three different B2subtypes.
Growth Factor‐Like Effects Mediated by Muscarinic Receptors in PC12M1 Cells
Authors: Pinkas‐Kramarski Ronit , Stein Reuven , Lindenboim Liora , Sokolovsky Mordechai
Published: July 2010

Abstract:Rat pheocromocytoma (PC12) cells stably expressing cloned m1 muscarinic acetylcholine receptors (PC12M1) undergo morphologic changes when stimulated by muscarinic agonists. These changes, which include the outgrowth of neurite‐like processes, are blocked by the muscarinic antagonist atropine and are not observed in PC12 cells. The observed morphological changes, which are independent of RNA and protein synthesis, are blocked by the methylation inhibitor 5′‐deoxy‐5′‐methylthioadenosine, suggesting that methylation plays a role in this process. Analysis of cyclic AMP accumulation and phosphoinositide turnover reveals that both processes are enhanced on activation by muscarinic agonist. Our data suggest, however, that the muscarinic‐dependent neurite‐like outgrowth processes are not mediated by cyclic AMP, Ca2+, or protein kinase C pathways. The muscarinic‐dependent neurite outgrowth effect is enhanced by nerve growth factor, with a resulting increase in both the number of neurite‐extending cells and the length of the neurite. In addition, activation of muscarinic receptors in PC12M1 cells stimulates the induction of marker genes for neuronal differentiation. Muscarinic receptors may therefore mediate growth factor‐like effects in these cells.
Neuropeptide Y Inhibits β‐Adrenergic Agonist– and Vasoactive Intestinal Peptide–Induced Cyclic AMP Accumulation in Rat Pinealocytes Through Pertussis Toxin–Sensitive G Protein
Authors: Harada Yumiko , Okubo Masashi , Yaga Ken , Kaneko Toshio , Kaku Kohei
Published: July 2010

Abstract:The effects of neuropeptide Y (NPY) on pineal gland cyclic AMP (cAMP) accumulation were investigated using dispersed pinealocytes from rats. NPY inhibited the intracellular cAMP accumulation stimulated by isoproterenol and norepinephrine in a dose‐dependent manner during a 10‐min incubation of pinealocytes. NPY (1 × 10−7M) also inhibited vasoactive intestinal peptide (VIP)‐ and cholera toxin–induced cAMP accumulation. The inhibitory effect of NPY on isoproterenol‐induced cAMP accumulation was completely abolished by a 5‐h pretreatment of pinealocytes with 1 μg/ml of pertussis toxin (PT). These results suggest that NPY participates in modulation of cAMP production in the rat pineal gland through PT‐sensitive G protein. Yohimbine, an α2‐adrenergic antagonist, blocked NPY inhibition of isoproterenol‐stimulated cAMP accumulation. On the other hand, the α2‐adrenergic agonist clonidine by itself did not affect cAMP accumulation stimulated by isoproterenol but significantly potentiated NPY action. The present study demonstrates that NPY inhibits β‐adrenergic or VIPergic stimulation of the pineal gland cAMP accumulation. The inhibitory effect of NPY is mediated through PT‐sensitive G protein. Our results also suggest that NPY exerts its action to affect α2‐adrenoceptor function.
Carboxypeptidase M in Brain and Peripheral Nerves
Authors: Nagae Akihiro , Deddish Peter A. , Becker Robert P. , Anderson Conwell H. , Abe Masahiro , Tan Fulong , Skidgel Randal A. , Erdös Ervin G.
Published: July 2010

Abstract:Carboxypeptidase M (CPM), a plasma membrane‐bound enzyme, cleaves C‐terminal basic amino acids with a neutral pH optimum. We studied its distribution in human, baboon, and dog brain and in dog peripheral nerves. Areas were dissected, homogenized, centrifuged, and assayed for activity with dansyl‐Ala‐Arg. The corpus callosum and the pyramidal and optic tract were especially rich in CPM, whereas basal ganglia and cortex had low activity. The identity of the basic carboxypeptidase activity with CPM was shown by similarities in subcellular localization, membrane attachment, substrate hydrolysis, inhibition by a specific basic carboxypeptidase inhibitor, and cross‐reaction with anti‐human CPM antiserum. This antiserum immunoprecipitated an average of 85% of the activity in human and baboon brain and ∼66% in dog brain. CPM copurified with myelin extracted from the brain. Consistent with results obtained in placenta and cultured kidney cells, CPM in the brain appears to be membrane‐bound via a phosphatidylinositol glycan anchor. In the peripheral nerves, the specific activity in dog sciatic nerve and in vagus was high (98 and 149 nmol/h/mg of protein, respectively). In immunohistochemical studies, glia in the brain, which appear to be oligodendrocytes or astrocytes, and the outer aspects of myelin sheaths and Schwann cells in sciatic and vagus nerves were stained. We conclude that in some areas of the CNS and the PNS, CPM is closely associated with myelin and myelin‐forming cells. Northern blot analysis revealed the presence of mRNA coding for CPM in the brain, showing that the enzyme is indeed synthesized there.
Effects of Electroconvulsive Shock on Tetrahydrobiopterin and GTP‐Cyclohydrolase Activity in the Brain and Adrenal Gland of the Rat
Authors: Hossain Mir Ahamed , Masserano Joseph M. , Weiner Norman
Published: July 2010

Abstract:The effects of a single and repeated electroconvulsive shock (ECS) (300 mA, 0.2 s) on tetrahydrobiopterin (BH4) levels and GTP‐cyclohydrolase activity in the brain and adrenal glands of rats were examined. Twenty‐four hours after the last ECS treatment (one/day for 7 days), biopterin levels were significantly elevated in the locus coeruleus, hippocampus, frontal cortex, hypothalamus, ventral tegmental area, and adrenal gland. There were no changes in biopterin levels after a single application of ECS. GTP‐cyclohydrolase activity was significantly increased in the locus coeruleus, frontal cortex, hippocampus, hypothalamus, and adrenal gland 24 h after repeated ECS and remained elevated in certain tissues up to 8 days after the last treatment. Kinetic analysis of adrenal and locus coeruleus GTP‐cyclohydrolase 1 day after 7 days of ECS showed significant changes in bothKmandVmaxvalues. These data suggest that the long‐term increases in BH4levels and GTP‐cyclohydrolase activity after repeated ECS may play a part in the mediation of the antidepressant effects of ECS.
Opioid‐Inhibited Adenylyl Cyclase in Rat Brain Membranes: Lack of Correlation with High‐Affinity Opioid Receptor Binding Sites
Authors: Nijssen Peter C. G. , Sexton Tammy , Childers Steven R.
Published: July 2010

Abstract:Opioid agonists bind to GTP‐binding (G‐protein)‐coupled receptors to inhibit adenylyl cyclase. To explore the relationship between opioid receptor binding sites and opioid‐inhibited adenylyl cyclase, membranes from rat striatum were incubated with agents that block opioid receptor binding. These agents included irreversible opioid agonists (oxymorphone‐p‐nitrophenylhydrazone), irreversible antagonists [naloxonazine, β‐funaltrexamine, and β‐chlornaltrexamine (β‐CNA)], and phospholipase A2. After preincubation with these agents, the same membranes were assayed for high‐affinity opioid receptor binding [3H‐labeled D‐alanine‐4‐N‐methylphenylalanine‐5‐glycine‐ol‐enkephalin (μ),3H‐labeled 2‐D‐serine‐5‐L‐leucine‐6‐L‐threonine enkephalin (δ), and [3H]ethylketocylazocine (EKC) sites] and opioid‐inhibited adenylyl cyclase. Although most agents produced persistent blockade in binding of ligands to high‐affinity μ, δ, and EKC sites, no change in opioid‐inhibited adenylyl cyclase was detected. In most treated membranes, both the IC50and the maximal inhibition of adenylyl cyclase by opioid agonists were identical to values in untreated membranes. Only β‐CNA blocked opioid‐inhibited adenylyl cyclase by decreasing maximal inhibition and increasing the IC50of opioid agonists. This effect of β‐CNA was not due to nonspecific interactions with Gi, Gs, or the catalytic unit of adenylyl cyclase, as neither guanylylimido‐diphosphate‐inhibited, NaF‐stimulated, nor forskolin‐stimulated activity was altered by β‐CNA pretreatment. Phospholipase A2decreased opioid‐inhibited adenylyl cyclase only when the enzyme was incubated with brain membranes in the presence of NaCl and GTP. These results confirm that the receptors that inhibit adenylyl cyclase in brain do not correspond to the high‐affinity μ, δ, or EKC sites identified in brain by traditional binding studies.
Possible Regulation of Caffeine‐Induced Intracellular Ca2+Mobilization by Intracellular Free Na+
Authors: Sorimachi Masaru , Yamagami Kazuhiko , Nishimura Shigeto , Kuramoto Kuniaki
Published: July 2010

Abstract:To gain some understanding of the regulatory mechanism involved in caffeine‐induced Ca2+release in adrenal chromaffin cells, we took advantage of the paradoxical observation that removal of divalent cations potentiated the secretory response to caffeine. We measured the concentration of cytosolic free Ca2+([Ca]in) in isolated cat chromaffin cells, by fura‐2 microfluorometry, to see whether there was any correlation between the secretory response and the rise in [Ca]in. The caffeine‐induced [Ca]inrise and catecholamine secretion were increased by treatment of cells with a divalent cation‐deficient solution. These potentiated responses were strongly inhibited either by pretreatment with ryanodine, by the reduction of the external Na+concentration, or by the addition of Ca2+channel blockers. Removal of divalent cations caused a large rise in the cytosolic free Na+concentration ([Na]in), which was measured using SBFI microfluorometry. This rise in [Na]inwas reduced either by adding Ca2+channel blockers or by reducing the external Na+concentration. These results show a good correlation between caffeine‐induced Ca2+release and [Na]inat the time of stimulation, suggesting that caffeine‐induced Ca2+release is regulated by [Na]in.
Phosphoinositide Turnover Associated with Synaptic Transmission
Authors: Murphy T. H. , Wright D. D. , Baraban J. M.
Published: July 2010

Abstract:Although pharmacological stimulation of a wide variety of transmitter receptors triggers phosphoinositide (PI) turnover, little is known about the type of synaptic activity required to activate this system. To investigate this question, we have used primary cultures of embryonic cortical neurons, which develop functional glutamate and GABA synapses during maturation in vitro. Mature cultures display spontaneous synaptic activity that is totally suppressed by tetrodotoxin (TTX). PI turnover, assayed by the lithium‐sensitive accumulation of [3H]CDP‐diacylglycerol, was readily detected under basal conditions and was abolished by TTX. Increased excitatory synaptic activity induced by picrotoxin, an antagonist of GABAAreceptor‐mediated inhibition, further stimulated PI turnover. Similar results were obtained when PI turnover was assayed using [3H]inositol labeling. With either assay, the magnitude of synaptically induced PI turnover was comparable to maximal responses produced by muscarinic receptor stimulation. Although a component of the spontaneous synaptic currents is sensitive toN‐methyl‐D‐aspartate (NMDA)‐preferring glutamate receptor antagonists, blockade of NMDA receptors did not affect PI turnover associated with synaptic transmission. To assess the time course of synaptically mediated PI turnover, the amplitude and duration of spontaneous synaptic currents were reduced by lowering the extracellular Ca2+concentration from 2.25 to 0.5 mM, a maneuver that suppresses basal PI turnover. Increases in PI turnover were detected as early as 5 min following restoration of the extracellular Ca2+concentration to 2.25 mM. Taken together, these findings indicate that activation of the PI system is associated with physiological levels of glutamatergic synaptic transmission.
Neurochemical Characterization of the Alterations in the Noradrenergic Afferents to the Cerebellum of Adult Rats Exposed to X‐Irradiation at Birth
Authors: Dopico Alejandro M. , Zieher Luis M.
Published: July 2010

Abstract:A single dose of x‐irradiation was applied on the cephalic end of newborn rats, and the alterations in the noradrenergic afferents to the cerebellum were studied 180 days later. A net increase in the noradrenaline content of cerebellum was found (122% of nonirradiated controls). The response of noradrenaline content to reserpine injection (0.9 mg/kg, i.p.) was similar in exposed and control rats. Likewise, the3H release induced by Ro 4‐1284 from cerebellar cortex slices labeled with [3H]noradrenaline was unmodified by x‐rays, although a mild increase in the spontaneous efflux of3H was found. The retention of3H by the slices was reduced in exposed animals (58% of controls). Both the in vitro activity of tyrosine hydroxylase and the accumulation of L‐3,4‐dihydroxyphenylalanine (L‐DOPA) were not significantly different between x‐treated rats and controls. In contrast, monoamine oxidase activity was markedly reduced in x‐irradiated cerebellum (38% of controls). The x‐ray‐induced decrease in cerebellar weight (—60%) resulted in marked increases in noradrenaline concentration (223%), tyrosine hydroxylase activity per milligram of protein (206%), and3H retention (50%). The accumulation of L‐DOPA per gram of tissue was also increased at every time considered. These data indicate that x‐irradiation at birth produces a cerebellar loss not completely shared by the noradrenergic afferents, and a permanent imbalance between the noradrenergic afferent input and its target cells might eventually result. In spite of the enhanced noradrenaline content, the lack of increase in maximal tyrosine hydroxylase activity and3H retention seems to indicate that a long‐term sprouting of the noradrenergic terminals in the cerebellum induced by the ionizing treatment is unlikely.
Micropurification of Two Human Cerebrospinal Fluid Proteins by High Performance Electrophoresis Chromatography
Authors: Leone Maria Grazia , Saso Luciano , Del Vecchio Alessandra , Mo Meng‐yun , Silvestrini Bruno , Cheng C. Yan
Published: July 2010

Abstract:Using C8 reversed‐phase HPLC in conjunction with sodium dodecyl sulfate‐polyacrylamide gel electrophoresis, we have fractionated proteins contained in human CSFs obtained from patients with schizophrenic disorders. When these proteins were electrophoretically blotted onto polyvinylidene difluoride membrane for direct N‐terminal amino acid sequencing, several CSF proteins were identified; these included albumin, transferrin, apolipoprotein A‐l, β2‐microglobulin, and prealbumin. We have also identified two structurally related human CSF proteins designated cerebrin 28 (Mr28,000) and cerebrin 30 (Mr30,000) that have an N‐terminal amino acid sequence of NH2‐APPAQVSVQPNF and NH2‐APEAQVSVQPLFXQ, respectively. Comparison of these sequences with existing database at Protein Identification Resource (R 32.0), GenBank (R 72.0), SWISS‐PROT (R 22.0), and EMBL (R 31.0) indicated that they are unique proteins. These proteins were subsequently purified by high performance electrophoresis Chromatography (HPEC) using an Applied Biosystems 230A HPEC system. A specific polyclonal antibody was prepared and an ELISA was established for cerebrin 30. It was noted that HPEC is a powerful tool to purify microgram quantities of proteins from human, rabbit, and rat CSFs. Using such a system, we have been able to micropurify as many as 10 proteins simultaneously in a single experiment because the elution of proteins occurred strictly according to their molecular weights. More importantly, we routinely obtained a recovery of >90%. The potential use of this technology for micropurification of proteins was discussed.
Attenuation of Excitatory Amino Acid Toxicity by Metabotropic Glutamate Receptor Agonists and Aniracetam in Primary Cultures of Cerebellar Granule Cells
Authors: Pizzi Marina , Fallacara Concetta , Arrighi Virginia , Memo Maurizio , Spano PierFranco
Published: July 2010

Abstract:Activation of glutamate ionotropic receptors represents the primary event in the neurotoxicity process triggered by excitatory amino acids. We demonstrate here that the concentration‐dependent stimulation of metabotropic glutamate receptor (mGluR) by the selective agonist trans‐1‐aminocyclopentane‐1, 3‐dicarboxylate or by quisqualate counteracts both glutamate‐ and kainate‐induced neurotoxicity in primary cultures of rat cerebellar granule cells. The mGluR‐evoked responses are potentiated by aniracetam, which per se also elicits neuroprotection. Aniracetam concentration‐dependently counteracted glutsmate‐, kainate‐, or α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid‐induced cell death and greatly facilitated neuroprotective response achieved by different concentrations of both quisqualate and trans‐1‐aminocyclopentane‐1, 3‐dicarboxylate. In addition, aniracetam potentiated the mGluR‐coupled stimulation of phospholipase C, as revealed by the measurement of3H‐inositol phosphate formation. Thus, mGluRs could be a suitable target for novel pharmacological strategies pointing to the treatment of neurodegenerative diseases.
Identification of the GABAAReceptor α3 Subunit in the IMR‐32 Neuroblastoma Cell Line
Authors: Noble Penelope J. , Anderson Shelagh M. P. , De Souza Rosemarie J. , Cross Alan J. , Stephenson F. Anne
Published: July 2010

Abstract:A previous report has described the presence of f‐[35S]‐ butylbicyclophosphorothionate binding sites and GABA‐gated CI flux in the human neuroblastoma IMR‐32 cell line. We now report the further characterisation of this binding site and, even more important, the identification of the GABAAreceptor α3 subunit expressed in these cells. Cell membranes prepared from IMR‐32 cells were screened by immunoblotting for reactivity with various GABAAreceptorasubunit‐specific antibodies. Of these, only anti‐Cys α3 454‐467 antibodies recognised specifically and in a dose‐dependent manner an immunoreactive band. This Mr58,000 immunoreactive species and theN‐deglycosylated derivatives were both coincident with the respective homologues found in both calf cerebral cortex membranes and purified receptor preparations. This is the first report of the identification of a specific GABAAreceptor subunit expressed in a human cell line, and it therefore provides a convenient model for the study of receptor structure and regulation.
Involvement of Intracellular Stores in the Ca2+ Responses to N‐Methyl‐D‐Aspartate and Depolarization in Cerebellar Granule Cells
Authors: Simpson Peter B. , Challiss R. A. John , Nahorski Stefan R.
Published: July 2010

Abstract: The [Ca2+]1 of cerebellar granule cells can be increased in a biphasic manner by addition of NMDA or by depolarization (induced by elevating the extracellular K+ level), which both activate Ca2+ influx. The possibility that these stimuli activate Ca2+‐induced Ca2+ release was investigated using granule cells loaded with fura 2‐AM. Dantrolene, perfused onto groups of cells during the sustained plateau phase of the [Ca2+]1 response to K+ or NMDA, was found to reduce the response to both agents in a concentration‐dependent manner. Preincubation with thapsigargm (10 μM) substantially reduced the plateau phase of the [Ca2+], response to K+ and both the peak and plateau phases of the NMDA response. Preincubation with ryanodine (10 μM) also reduced both the K+‐evoked plateau response and both phases of the NMDA response. Neither had a consistent effect on the peak response to K+. The effects of thapsigargin and ryanodine on the NMDA response were partially additive. These results demonstrate that in cerebellar granule cells a major component of both K+‐ and NMDA‐induced elevation of [Ca2+]1 appears to be due to release from intracellular stores. The partial additivity of the effects of thapsigargin and ryanodine suggests that these agents affect two overlapping but nonidentical Ca2+ pools.
Overexpression of Heme Oxygenase‐1 Is Neuroprotective in a Model of Permanent Middle Cerebral Artery Occlusion in Transgenic Mice
Authors: Panahian Nariman , Yoshiura Masako , Maines Mahin D.
Published: July 2010

Abstract: Heme oxygenase‐1 (HO‐1, HSP32) is an early gene that is responsive to an array of pathological conditions including, but not limited to, hypoxia and cerebral ischemia. HO‐1 cleaves the heme molecule and produces carbon monoxide (CO) and biliverdin (an antioxidant) and is essential for iron homeostasis. The purpose of this study was to investigate, using transgenic (Tg) mice, whether overexpression of HO‐1 in the brain augments or attenuates cellular injury caused by ischemic stroke. Homozygous HO‐1 Tg mice that overexpress HO‐1 under the control of the neuron‐specific enolase promoter (characterized previously) were used. Under halothane anesthesia and normothermic conditions, wildtype nontransgenic (nTg ; n = 22) and HO‐1 Tg (n = 24) mice were subjected to middle cerebral artery occlusion (MCAo). Six hours after induction of ischemia, Tg and nTg mice developed infarcts that were 39 ± 6 and 63 ± 9 mm3, respectively (p< 0.01). No significant difference between the two strains was observed in the values of brain edema (11.3 ± 4% in Tg vs. 14.6 ± 5% in nTg ;p< 0.1). At 24 h after MCAo, Tg mice exhibited significant neuroprotection as determined by the stroke volumes (41 ± 2 mm3in Tg vs. 74 ± 5 mm3in nTg ;p< 0.01) and values of ischemic cerebral edema (21 ± 6% in Tg vs. 35 ± 11% in nTg ;p< 0.01). Data suggest that neuroprotection in Tg mice was, at least in part, related to the following findings : (a) constitutively up‐regulated cyclic GMP and bcl‐2 levels in neurons ; (b) inhibition of nuclear localization of p53 protein ; and (c) antioxidant action of HO‐1, as detected by postischemic neuronal expression of ferritin, and decreases in iron staining and tissue lipid peroxidation. We suggest that pharmacological stimulation of HO‐1 activity may constitute a novel therapeutic approach in the amelioration of ischemic injury during the acute period of stroke.
Dephosphorylation of microtubule‐associated protein tau by protein phosphatase 5
Authors: Gong Cheng‐Xin , Liu Fei , Wu Guoxin , Rossie Sandra , Wegiel Jerzy , Li Liang , Grundke‐Iqbal Inge , Iqbal Khalid
Published: July 2010

Protein phosphatase 5 (PP5) is a 58‐kDa novel phosphoseryl/phosphothreonyl protein phosphatase. It is ubiquitously expressed in all mammalian tissues examined, with a high level in the brain, but little is known about its physiological substrates. We found that this phosphatase dephosphorylated recombinant tau phosphorylated with cAMP‐dependent protein kinase and glycogen synthase kinase‐3β, as well as abnormally hyperphosphorylated tau isolated from brains of patients with Alzheimer's disease. The specific activity of PP5 toward tau was comparable to those reported with other protein substrates examined to date. The PP5 activity toward tau was stimulated by arachidonic acid by 30‐ to 45‐fold. Immunostaining demonstrated that PP5 was primarily cytoplasmic in PC12 cells and in neurons of postmortem human brain tissue. A small pool of PP5 associated with microtubules. Expression of active PP5 in PC12 cells resulted in reduced phosphorylation of tau, suggesting that PP5 can also dephosphorylate tau in cells. These results suggest that PP5 plays a role in the dephosphorylation of tau and might be involved in the molecular pathogenesis of Alzheimer's disease.
Neurochemical and behavioural changes in zebrafishDanio rerioafter systemic administration of 6‐hydroxydopamine and 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine
Authors: Anichtchik Oleg V. , Kaslin Jan , Peitsaro Nina , Scheinin Mika , Panula Pertti
Published: July 2010

Dopaminergic deficiency in the brain of zebrafish was produced by systemic administration of two catecholaminergic neurotoxins, 6‐hydroxydopamine (6‐OHDA) and 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP), and the neurochemical and behavioural changes were characterized. The levels of dopamine and noradrenaline decreased significantly after the injection of MPTP and 6‐OHDA. Corresponding to these changes, fish exhibited characteristic changes in locomotor behaviour, i.e. the total distance moved and velocity decreased after both neurotoxins. Tyrosine hydroxylase and caspase 3 protein levels were not altered after MPTP or 6‐OHDA injections, as studied by immunohistochemistry and western blotting. The catecholaminergic cell clusters suggested to correspond to the mammalian nigrostriatal cell group displayed normal tyrosine hydroxylase immunoreactivity after the toxin treatment and did not show signs of DNA fragmentation that would indicate activation of cascades that lead to cell death. The results show that single systemic injections of MPTP and 6‐OHDA induce both biochemical and behavioural changes in zebrafish, albeit failing to produce any significant morphological alteration in catecholaminergic cell clusters at the tested doses. This approach may be used for the screening of chemicals affecting the dopaminergic system. The model may be especially useful for evaluation of the role of novel genes in neurotoxicity, as a large number of zebrafish mutants are becoming available.
5‐HT2Creceptor activation prevents stress‐induced enhancement of brain 5‐HT turnover and extracellular levels in the mouse brain: modulation by chronic paroxetine treatment
Authors: Mongeau Raymond , Martin Cédric B. P. , Chevarin Caroline , Maldonado Rafael , Hamon Michel , Robledo Patricia , Lanfumey Laurence
Published: July 2010

J. Neurochem.(2010)115, 438–449.

Stress is known to activate the central 5‐hydroxytryptamine (5‐HT) system, and this is probably part of a coping response involving several 5‐HT receptors. Although 5‐HT2Creceptors are well known to be implicated in anxiety, their participation in stress‐induced changes had not been investigated in parallel at both behavioral and neurochemical levels. We show here that the preferential 5‐HT2Creceptor agonist, m‐chlorophenylpiperazine, as well as restraint stress increased anxiety in the mouse social interaction test. The selective 5‐HT2Creceptor antagonist, SB 242,084, prevented both of these anxiogenic effects. Restraint stress increased 5‐HT turnover in various brain areas, and this effect was prevented by the 5‐HT2B/2Creceptor agonist RO 60‐0175 (1 mg/kg), but not the preferential 5‐HT2Aagonist 1‐(2,5‐dimethoxy‐4‐iodophenyl)‐2‐aminopropane (1 mg/kg), and in contrast potentiated by SB 242,084 (1 mg/kg), which also blocked the effect of RO 60‐0175. Using microdialysis, RO 60‐0175 was shown to inhibit cortical 5‐HT overflow in stressed mice when 5‐HT reuptake was blocked locally. Chronic paroxetine prevented both the anxiogenic effect of m‐chlorophenylpiperazine and the inhibitory effect of RO 60‐0175 on locomotion and stress‐induced increase in 5‐HT turnover. The anxiolytic action of chronic paroxetine might be associated with an enhancement of 5‐HT neurotransmission caused by a decreased 5‐HT2Creceptor‐mediated inhibition of stress‐induced increase in 5‐HT release.
Aldose Reductase and AGE–RAGE pathways: central roles in the pathogenesis of vascular dysfunction in aging rats
Authors: Hallam Kellie McCormick , Li Qing , Ananthakrishnan Radha , Kalea Anastasia , Zou Yu S. , Vedantham Srinivasan , Schmidt Ann Marie , Yan Shi Fang , Ramasamy Ravichandran
Published: July 2010

Aging is inevitably accompanied by gradual and irreversible innate endothelial dysfunction. In this study, we tested the hypothesis that accentuation of glucose metabolism via the aldose reductase (AR) pathway contributes to age‐related vascular dysfunction. AR protein and activity levels were significantly increased in aged vs. young aortic homogenates from Fischer 344 rats. Immunostaining revealed that the principal site of increased AR protein was the aortic endothelium as well as smooth muscle cells. Studies revealed that endothelial‐dependent relaxation (EDR) in response to acetylcholine was impaired in aged rats compared to young rats and that treatment with the AR inhibitor (ARI) zopolrestat significantly improved EDR in aged rats. Methylglyoxal (MG), a key precursor of advanced glycation endproducts (AGEs), was significantly increased in the aortas of aged rats vs. young rats. Consistent with central roles for AR in generation of MG in aging, ARI treatment significantly reduced MG levels in aged rat aorta to those in young rats. Treatment of aged rats with soluble(s) RAGE, a soluble form of the chief signal transduction receptor for AGEs, RAGE, significantly improved EDR in aged rats, thus establishing the contribution of age‐related increases in AGEs to endothelial dysfunction. These findings reveal that significant increases in AR expression and activity in aged rat vasculature linked to endothelial dysfunction may be mitigated, at least in part, via ARI and that aging‐linked increased flux via AR generates AGEs; species which transduce endothelial injury consequent to their interaction with RAGE. These data demonstrate for the first time that AR mediates aging‐related vascular dysfunction, at least in part, via RAGE.
The Cellulose‐Dyestuff Complex. Part II– The Intensity of Light Reflected from Dyed Fibres*
Authors: PRESTON J. M. , TSIEN P. C.
Published: July 2010

A model is proposed from which to calculate the light reflected from dyed fibres. An explicit relation between reflected light intensities and dye concentrations is derived from the model and gives a reasonable fit to experimental measurements on dyed fibres.
The Reactivity of the Sulphur Linkage in Animal Fibres
Authors: FARNWORTH A. J. , NEISH W. J. P. , SPEAKMAN J. B.
Published: July 2010

In order to teat the view that reagents such as chlorine, sulphuryl chloride, and sodium hydroxide make wool unshrinkable by promoting disulphide bond breakdown in the surface of the fibres, the action of these reagents on wools containing other types of cross–linkage in place of cystine has been examined. Four kinds of wool have been used, viz. (1) wool reduced with thioglycollic acid and treated with mercuric oyanide to form –S. Hg. S– cross–linkages, (2) wool reduced with thioglycollic acid and treated with trimethylene dibromide to form bisthioether cross–linkages, (3) alkali–treated wool containing Ianthionine and, presumably, –CH: N– cross–linkages, and (4) wool treated with potassium cyanide to convert most or all of the cystine into Ianthionine. In all cases, the modified wool was more difficult to make unshrinkable than untreated wool, though the difference was small with types (1) and (2). Very successful results were obtained with the alkali–treated wool (3), and complete immunity to the action of chlorine, sulphuryl chloride, and potassium hydroxide, as regards the development of resistance to shrinkage, was obtained with wool treated with potassium cyanide (4). Since the action of potassium cyanide is to convert disulphide bonds into Ianthionine cross–linkages, there can be little doubt, therefore, that the above reagents make normal wool unshrinkable by causing disulphide bond breakdown.
Radio–frequency Drying of Textile Fabrics
Authors: ALEXANDER P. , MEEK G. A.
Published: July 2010

An apparatus for studying the drying of textile fabrics by high–frequency (dielectric) heating is described. Rate–of–drying curves for thirteen different textile materials, together with measurements of temperature and power consumption, are shown. With every material examined the drying curve shows a discontinuity and the rate of drying decreases at a certain moisture content, which in most cases approximates closely to the reported figures for saturation regain of the respective fibres. The water held by fibres at this moisture content is not free and has anomalous electrical properties. The practical advantages of high–frequency drying are discussed,
The Estimation of Anionic Detergents in Solution by Hartley Titrations
Authors: Swanston Kathleen , Palmer R. C.
Published: July 2010

A quick method for the estimation of anionic detergents is given. It is a modification of Hartley and Runnicles' method, no indicator being used, and either cationic or anionic detergent can be used in the burette. The method is shown to be at least as accurate as other published methods and is quicker and more straightforward.
Developments in the Application of Sulphur Dyes to Loose Cotton and Yarns
Authors: Birchall H.
Published: July 2010

The evolution of sulphur dyes is briefly reviewed, and the dyeing of loose cotton and sliver outlined. Yarn dyeing is described under the headings of hank, warp, and package dyeing, and the aftertreatment of sulphur dyeings is discussed. Finally, the application of water‐soluble types of sulphur dyes is described.
A Study of the Alkali Solubility Test for Determining the Degree of Fibre Damage in Wool
Authors: Lees K. , Elsworth F. F.
Published: July 2010

Existing methods for the determination of the alkali solubility of wool have been examined, especially in respect of their reproducibility. The physical state, e.g. yarn or fabric, in which the material is tested has been found to have considerable influence on the results. The effect of processes known to give rise to an increase in alkali solubility has been investigated with the object of giving significance to results on commercially processed materials. Examples are given of the use of the test in the examination of faults.
Some Aspects of the Mechanical Finishing of Cotton Textiles
Authors: Nabar G. M. , Tawde G. P.
Published: July 2010

Some aspects of mechanical finishing processes for cotton textiles, mainly calendering, have been examined, and the influences of heat, pressure, moisture content, and starch content on the resultant finish investigated.

An increase in moisture content of the fabric during calendering produces the following effects on the finished samplesndashincrease in stiffness and lustre, decrease in thickness, loss in textile qualities, and increase in resistance to abrasion. On storage, both the stiffness and the lustre of the calendered fabric show a gradual fall, With softening agents, the stage at which they are added to the starch paste determines the viscosity of the paste and the stiffness of the fabric. Studies on soluble starches show that for pastes of the same viscosity the stiffness of the fabric depends on the amount of the starch taken up and on the concentration of the starch.
The Importance of Temperature and Relative Humidity in Light Fastness Testing
Authors: McLAREN K.
Published: July 2010

Differences in temperature during exposure are unlikely to be a direct cause of anomalous results in light fastness testing; differences in effective humidity, however, are of extreme importance and can cause variations of as much as four grades. The effective humidity during daylight exposure in Great Britain by the method specified in B.S. 1006: 1955 has an average value of 20%. Fading lamps should be operated at the same value: the effective humidity in certain lamps is too low and cannot be increased; in others it is too high when running under the makers' recommendations, but in such cases the preferred value can be easily obtained.
A Note on the Diffusion of Disperse Dyes in Nylon Yarn
Authors: Bied C. L. , Scott D. E.
Published: July 2010

Diffusion coefficients and times of half‐dyeing have been determined for three commercial anthra‐quinonoid disperse dyes on nylon yarn. The results support the view that rate of dyeing is mainly governed by rate of diffusion of dye in the fibre.
The Effect of Sulphuric Acid on Wool
Authors: Elliott R. L. , Asquith R. S. , Rawson D. H.
Published: July 2010

Investigation of wool samples after various times of treatment with concentrated sulphurio acid has shown that hydrolysable sulphate increases to a maximum after 1 hr, A fall in sulphate after 1 day to a relatively constant value corresponds to the loss of a scaly membrane. A slow increase in total sulphur is due to removal of the low‐oystine‐containing fraction of the fibre and to slow benzene‐ring sulphonation.

Hydrolysates of wool treated with sulphurio acid contain substances identical with those produced on sulphonation of amino acids. Histological changes observed microscopically agree with the results of chemical analysis.
The Dyeing of Nylon with Acid and Mordant Dyes at High Temperatures
Authors: Hadfield H. R. , Seaman H.
Published: July 2010

A study has been made of the stability of acid and chrome dyes in solution at temperatures above 100°c. The effects of an increase in dyeing temperature above 100°c. on the levelling of acid dyes and upon the rate of chroming of chrome dyes have also been determined. The results emphasise the importance of controlling the exhaustion of the dyebath during the dyeing of nylon and confirm the rapid rate of chroming above 100°c.
Some Physical Properties of Chemically Finished Viscose Rayon Filament Yarns and Fabrics
Authors: Morton D. H. , Beaumont C.
Published: July 2010

The physical properties of viscose rayon filament yarns have been studied before and after treatment with a wide range of resin and formaldehyde finishes applied by normal, as well as unconventional, methods. A general relationship has been observed between the tensile elastic recovery, extensibility, wet initial modulus and water imbibition of chemically finished rayon yarns. The changes in tensile and other properties are described, and discussed with regard to their influence on resultant fabric properties. The finisher must compromise between improvement in some properties and impairment of others. This balance of yarn properties is unaffected by the type of treatment used, although widely different amounts of the various resins have to be used for similar effects. The choice of finish is governed by factors other than the effect on yarn tensile properties. Examples of such factors are liability to form inter‐fibre resin deposits, frictional characteristics, fastness of the finish to various agencies, and fabric aesthetics.
A Study of the Chemistry of Carrotting Processes
Authors: Robinson E. A. , Robinson Janice
Published: July 2010

The simplest non‐mercuric carrotting solution, hydrogen peroxide and nitric acid, reacts with both cystine and tyrosine in rabbit fur. There is evidence that nitrous acid is a by‐product of the oxidation of cystine by these reagents and, under the special conditions which prevail inside the fur fibre, this intermediate may play an important part in subsequent reactions and especially in the nitration of tyrosine side‐chains.
The Problem of Illumination in Colour Matching
Authors: McLaren K.
Published: July 2010

The factors which govern the suitability of any light source, including the various phases of daylight, for colour matching are discussed from a theoretical standpoint and a review is made of the experimental data available. It is concluded that colour‐matching lamps should be standardised to reproduce the spectral quality of total daylight (colour temperature about 6250K) rather than north‐sky daylight (about 7400K). Spectral‐distribution curves of total daylight are critically reviewed to determine their suitability for this purpose. If, however, it is ultimately decided that colour‐matching lamps should imitate north‐sky daylight, the phase of daylight actually used by professional colour matchers, then Illuminant C is no longer suitable as the standard source for colour matching: lamps emitting light similar in spectral distribution to the Abbot–Gibson 7400K curve, extended to 300 mμ, would be expected to be suitable. The relevant topic of variation in colour vision is discussed and a review is made of commercial colour‐matching lamps.
Setting Wool at Low Extensions in High‐temperature Steam
Authors: Orwell R. L. , Datyner A. , Nicholls C. H.
Published: July 2010

The setting of wool held at 3% and 10% extension in saturated steam at temperatures above 100°C has been investigated, the times and temperatures of steaming and the pH of the wool being varied. Experiments were carried out both on single fibres and on aligned bundles of fibres. It was shown that, over the pH range 3·0–9·2, steaming for 15 min at 115°C is sufficient to produce a considerable degree of set, stable to release in water at 100°C for one hour.
The Preparation and Properties of Cellulose containing Polyacrolein
Authors: WORTH SUSAN HA , HOLKER J. R.
Published: July 2010

Redox–initiated polymerisation of acrolein in viscose rayon and cotton constitutes a novel method for the introduction of cross–links into cellulose under mild conditions. The products have good crease recovery but poor tear strength and resistance to abrasion. Polyacrolein is, however, unstable to alkali and is removed from cellulose by hot sodium carbonate–soap solution; irregularities in the structure of the polymer are held to account for this instability. The cross–links between polyacrolein and cellulose, which probably have a hemiacetal structure, are destroyed by reduction with sodium borohydride, which yields an alkali–resistant product, and by reaction with urea. Typical carbonyl–group reagents combine to a limited extent with polyacrolein–cellulose, and some of the derivatives have improved resistance to microbial attack.
Migration during Convective Drying. I‐Theoretical
Authors: MCDOWELL W. , MEADLEY C. K. , MILES L. W. C.
Published: July 2010

A model is proposed which makes possible the mathematical treatment of the movement of solute resulting from the evaporation of solvent from the surface of a capillary network. It is considered useful in predicting the migration of solute in the capillaries of a textile material during the constant–rate period of convective drying. Within the limits of certain simplifying assumptions, the concentration depth profiles are defined as a function of time by the solution to the equation of Fick's second law of diffusion satisfying defined boundary conditions.
Continuous and Quantitative Polarographic Analysis of Dithionites
Authors: LEM W. J. , WAYMAN M.
Published: July 2010

Amperometric titration, using either a dropping‐mercury electrode or a rotating platinum electrode as the indicator electrode and Rubine as the titrant, has been shown to be a useful method of analysis of sodium and zinc dithionites. From controlled potential electrolysis, it was confirmed that the anodic oxidation of dithionite involves two electrons per dithionite ion, sulphite being identified polarographically as one of the products of the reaction. A continuous voltammetric determination of dithionite is described that could possibly be adapted for the control of industrial processes in which dithionite is used.
Discoloration of Nylon 6.6—A Comparison of some Contributory Factors
Authors: BYRNE G. A. , HOLMES F. H. , LORD Mrs J.
Published: July 2010

A wear trial of full‐length white nylon underskirts was conducted to compare the contributions to discoloration due to changes in the nylon polymer, to the spin finish, to a fluorescent brightener, to the soap used in washing, to skin fat, and to air‐borne dirt. The underskirts, in absence and in presence of spin finish and of brightener, were worn according to a schedule and washed in a standardised way using a low concentration of soap. Greyness and yellowness increased steadily, the greyness being greater in the upper than in the lower parts of the garments. After the wear trial, retained fat was extracted from the garments with organic solvents, weighed and analysed. The high discoloration found in all garments was due mainly to the absorption of skin fat and soap and the associated retention of particulate dirt. Fat and yellow colouring matter could be transferred during washing. Spin finish and fluorescent brightener usually only slightly affected the discoloration. There was negligible discoloration due to the storage of the nylon, repeated washing of clean fabric, and repeated exposure to dirty air followed by washing.