Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 86
Filtrar
Más filtros

Bases de datos
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Phys Rev Lett ; 127(25): 257001, 2021 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-35029441

RESUMEN

The Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state, characterized by Cooper pairs condensed at finite momentum, has been a long-sought state that remains unresolved in many classes of fermionic systems, including superconductors and ultracold atoms. A fascinating aspect of the FFLO state is the emergence of periodic nodal planes in real space, but its observation is still lacking. Here we investigate the superconducting order parameter at high magnetic fields H applied perpendicular to the ab plane in a high-purity single crystal of FeSe. The heat capacity and magnetic torque provide thermodynamic evidence for a distinct superconducting phase at the low-temperature/high-field corner of the phase diagram. Despite the bulk superconductivity, spectroscopic-imaging scanning tunneling microscopy performed on the same crystal demonstrates that the order parameter vanishes at the surface upon entering the high-field phase. These results provide the first demonstration of a pinned planar node perpendicular to H, which is consistent with a putative FFLO state.

2.
Biochem Biophys Res Commun ; 503(2): 1141-1147, 2018 09 05.
Artículo en Inglés | MEDLINE | ID: mdl-29944883

RESUMEN

This paper reports isolation of two monoclonal antibodies (mAbs) that bind to both a membrane protein and a cytoplasmic protein. Most Abs established as markers for autoimmune disease bind to cytoplasmic or nuclear substances. However, it remains unknown how these Abs are produced. On the other hand, there were examples where clones originally isolated as Abs that bind to membrane proteins also showed binding activity to cytoplasmic or nuclear substances. Based on these results, the following hypothesis has been proposed. The Abs that had been originally produced against a membrane protein showed cross-reactivity against cytoplasmic or nuclear substances. In the present study we reported isolation of Abs that bound to both a membrane protein, CADM1, and a cytoplasmic protein, α-actinin-4. The method adopted in the present study could be generally applicable to isolation of Abs showing such dual specificity. Firstly, we constructed a huge human Ab library using various organs including naïve B-cell-rich organs such as bone marrow and umbilical cords. Then, we developed a comprehensive screening method for isolation of Abs that bound to cell surface antigens. Through extensive screenings with many kinds of cell we newly obtained a library composed of around 4000 independent clones that bind to membrane proteins. We screened this library with α-actinin-4 and succeeded in isolating two Abs. They bound to α-actinin-4 and a membrane protein CADM1. Furthermore, they are encoded by naïve heavy and light chain variable genes (VH & VL). These results suggested that cross-reactive Abs to both a membrane protein and a cytoplasmic protein could be present in germline repertoire of Ab in humans. This methodology adopted in the present study could be applied to isolation of cross-reactive Abs possibly involved in autoimmune diseases.


Asunto(s)
Actinina/inmunología , Anticuerpos Monoclonales/inmunología , Molécula 1 de Adhesión Celular/inmunología , Secuencia de Aminoácidos , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/genética , Línea Celular , Reacciones Cruzadas , Células Hep G2 , Humanos , Región Variable de Inmunoglobulina/química , Región Variable de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/inmunología , Inmunoprecipitación
3.
Eur J Paediatr Dent ; 17(2): 155-63, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27377116

RESUMEN

AIM: To investigate the developmental process of palate morphology, including the alveolar ridge, in healthy infants for the predental period of 7 months from immediately after birth. METHODS: The subjects were 32 healthy infants. Four or more dental casts were taken of each subject from immediately after birth until 7 months, for a total of 144 dental casts. Twelve characteristics were then measured in order to morphologically study the subjects' palate development. Principal component analysis (PCA) was performed to investigate morphological changes in the palatal vault. RESULTS: The 12 characteristics were classified into either the alveolar ridge characteristics group, which determined the size of the alveolar ridge, or the palate characteristics group, which determined palate morphology, with each group showing different growth patterns. The characteristics of width and length increased with age in the alveolar ridge characteristics group; this correlation was maintained throughout the predental period. Meanwhile, in the palate characteristics group, the characteristics showed major developmental changes in the first 2 to 3 months after birth, but the changes were subsequently fewer from 3 to 7 months. The PCA of the palatal vault showed that the first principal component increased until 3 months but subsequently ceased to change. CONCLUSIONS: In predental infants, growth patterns of palate morphology differed according to their characteristics. There were major developmental changes in the palate during the first 3 months after birth. The study findings suggest that palate growth in the first half of the predental period may affect subsequent palate growth.


Asunto(s)
Proceso Alveolar/crecimiento & desarrollo , Hueso Paladar/crecimiento & desarrollo , Dentición , Humanos , Lactante , Estudios Longitudinales
4.
Genetics ; 136(2): 693-704, 1994 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8150292

RESUMEN

In this study we show how the genetic variance of a quantitative trait changes in a self-fertilizing population under repeated cycles of truncation selection, with the analysis based on the infinitesimal model in which it is assumed that the trait is determined by an infinite number of unlinked loci without epistasis. The genetic variance is reduced not as a consequence of the genotypic frequency change but due to the build-up of linkage disequilibrium under truncation selection in this model. We assume that the order of the genotypic contribution from each locus is n-1/2, where n is the number of loci involved, and investigate the change in linkage disequilibrium resulting from selection and self-fertilization using genotypic frequency dynamics in order to analyze the change in the genetic variance. Our analysis gives recurrence relations of genetic variance among the succeeding generations for the three cases of gene action, i.e., purely additive action, pure dominance without additive effect and the presence of both additive effect and dominance, respectively. Numerical examples are also given as a check on the recurrence formulas.


Asunto(s)
Selección Genética , Fertilización , Genotipo , Desequilibrio de Ligamiento , Método de Montecarlo , Fenotipo
5.
Genetics ; 158(1): 463-75, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11333253

RESUMEN

The existence of a quantitative trait locus (QTL) is usually tested using the likelihood of the quantitative trait on the basis of phenotypic character data plus the recombination fraction between QTL and flanking markers. When doing this, the likelihood is calculated for all possible locations on the linkage map. When multiple QTL are suspected close by, it is impractical to calculate the likelihood for all possible combinations of numbers and locations of QTL. Here, we propose a genetic algorithm (GA) for the heuristic solution of this problem. GA can globally search the optimum by improving the "genotype" with alterations called "recombination" and "mutation." The "genotype" of our GA is the number and location of QTL. The "fitness" is a function based on the likelihood plus Akaike's information criterion (AIC), which helps avoid false-positive QTL. A simulation study comparing the new method with existing QTL mapping packages shows the advantage of the new GA. The GA reliably distinguishes multiple QTL located in a single marker interval.


Asunto(s)
Algoritmos , Ligamiento Genético , Carácter Cuantitativo Heredable , Modelos Genéticos , Selección Genética
6.
J Immunol Methods ; 257(1-2): 175-84, 2001 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11687251

RESUMEN

We developed a system by which antibodies, fused to fluorescent proteins with different wavelengths, can be prepared within a month against various antigens. An antibody library composed of a large number of single-chain Fv-CL fragment was constructed by means of a phage-display system. The constructs were designed to facilitate changing of the protein forms by simple enzyme manipulation. In the present study, we adopted a molecular form of antibody in which a single-chain Fv-CL fragment is fused with a green fluorescent protein (GFP) or red fluorescent protein (RFP). In addition, a His-tag was inserted between CL and GFP (or RFP). We describe the utility of this system using Caenorhabditis elegans embryo as a model.


Asunto(s)
Anticuerpos/genética , Perfilación de la Expresión Génica/métodos , Proteínas Luminiscentes/genética , Secuencia de Aminoácidos , Animales , Antígenos Helmínticos/genética , Secuencia de Bases , Caenorhabditis elegans/embriología , Caenorhabditis elegans/genética , Caenorhabditis elegans/inmunología , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/inmunología , Proteínas Portadoras/genética , Proteínas Portadoras/inmunología , Escherichia coli/genética , Vectores Genéticos , Proteínas Fluorescentes Verdes , Fragmentos de Inmunoglobulinas/genética , Indicadores y Reactivos , Ratones , Datos de Secuencia Molecular , Biblioteca de Péptidos , Proteínas de Unión al ARN , Proteínas Recombinantes de Fusión/genética , Proteína Fluorescente Roja
7.
Neuropharmacology ; 39(7): 1319-30, 2000 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-10760374

RESUMEN

The changes in nitric oxide (NO) formation during hypoxia and reoxygenation were measured in slices of rat cerebral cortex, and the possible involvement of NO and its decomposition products, including peroxynitrite and hydroxyradical, in the hypoxia/reoxygenation injury was subsequently investigated. NO formation estimated from cGMP accumulation in the extracellular fluids was enhanced during hypoxia and to a lesser extent in the reoxygenation period. The mRNA for inducible NO synthase (NOS) was detected 3-5 h after reoxygenation, although neuronal NOS mRNA decreased after reoxygenation. Several NOS inhibitors such as N(G)-monomethyl-L-arginine and N(G)-nitro-L-arginine blocked not only the NO formation but also the hypoxia/reoxygenation injury as determined by lactate dehydrogenase (LDH) leakage. The hypoxia/reoxygenation injury was prevented by peroxynitrite scavengers including deferoxamine and uric acid, or several hydroxyradical scavengers such as dimethylthiourea, 2-mercaptopropionylglycine and D(-) mannitol. In addition, the hypoxia/reoxygenation injury was attenuated by poly(ADP-ribose)synthetase inhibitors such as banzamide, 3-aminobenzamide and 1,5-isoquinolinediol. On the other hand, both N-morpholinosidnonimine, a peroxynitrite generator, and hydroxyradical-liberating solution containing FeCl(3)-ADP and dihydroxyfumarate caused a marked LDH leakage in normoxic slices. These findings suggest that the enhanced formation of NO causes hypoxia/reoxygenation injury after degradation to peroxynitrite and hydroxyradical and the resultant activation of poly(ADP-ribose)synthetase.


Asunto(s)
Corteza Cerebral/metabolismo , Radical Hidroxilo/metabolismo , Hipoxia/metabolismo , Nitratos/metabolismo , Óxido Nítrico/metabolismo , Oxidantes/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Sistema Libre de Células , Corteza Cerebral/patología , AMP Cíclico/metabolismo , Inhibidores Enzimáticos/farmacología , Hipoxia/patología , Masculino , Neuronas/efectos de los fármacos , Neuronas/enzimología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Óxido Nítrico Sintasa/biosíntesis , Óxido Nítrico Sintasa de Tipo II , Inhibidores de Poli(ADP-Ribosa) Polimerasas , ARN Mensajero/biosíntesis , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Salicilatos/metabolismo , Tirosina/metabolismo
8.
Brain Res ; 890(1): 162-9, 2001 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-11164779

RESUMEN

The effect of a novel Na+/Ca2+ channel blocker NS-7 [4-(4-fluorophenyl)-2-methyl-6-(5-piperidinopentyloxy)pyrimidine hydrochloride] on the cerebral infarction, edema and brain energy metabolism was investigated in rats after permanent middle cerebral artery occlusion (MCAO). The infarction and brain water content were evaluated at 48 h and 24 h after MCAO, respectively. A single bolus injection of NS-7 (0.03125-0.25 mg/kg) immediately after MCAO produced a dose-dependent reduction in the infarct volume as well as edema both in the cerebral cortex and striatum. Glycerol (4 g/kg) also decreased water content both in the occluded and non-occluded brain, but it did not reduce the size of cerebral infarction. Unlike glycerol, NS-7 did not change the water content in non-occluded brain. Moreover, a significant protective action was still observed even when NS-7 was injected once at 12 h after occlusion. In addition, NS-7 significantly reversed the decrease in tissue ATP content observed at 3 h but not at 0.5 h after MCAO. These findings suggest that a Na+/Ca2+ channel blocker NS-7 protects cerebral tissues against ischemic insults by improving the disturbance of cerebral energy metabolism and suppressing the cerebral edema.


Asunto(s)
Edema Encefálico/tratamiento farmacológico , Infarto Cerebral/tratamiento farmacológico , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Fármacos Neuroprotectores/farmacología , Pirimidinas/farmacología , Adenosina Difosfato/metabolismo , Adenosina Monofosfato/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Encéfalo/irrigación sanguínea , Encéfalo/metabolismo , Edema Encefálico/patología , Bloqueadores de los Canales de Calcio/farmacología , Infarto Cerebral/patología , Crioprotectores/farmacología , Glicerol/farmacología , Infarto de la Arteria Cerebral Media/patología , Masculino , Ratas , Ratas Sprague-Dawley , Bloqueadores de los Canales de Sodio
9.
Brain Res ; 890(1): 170-6, 2001 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-11164780

RESUMEN

We have previously shown that NS-7 [4-(4-fluorophenyl)-2-methyl-6-(5-piperidinopentyloxy)pyrimidine hydrochloride] reduces the size of cerebral infarction measured by 2,3,5-triphenyltetrazolium chloride staining at 48 h after permanent middle cerebral artery occlusion (MCAO) in rats. To determine whether NS-7 improves the pathological and behavioral changes at the chronic stage of MCAO, the effect of this compound on the cerebral infarction as well as the neurological and cognitive impairments was investigated 7 days after MCAO. Single or five daily injections of NS-7 (0.125-0.5 mg/kg, i.v.) significantly reduced the infarct volume and improved the neuronal dysfunction including the hind leg paralysis, walking disability and motor incoordination, and the deficit of passive avoidance task, although the neuroprotective efficacy was not different among these dosing regimens. On the other hand, the effects of single versus repeated injections of NS-7 at 0.1 or 0.2 mg/kg on the neurological symptoms were compared at 4 weeks after MCAO. At a lower dose, repeated but not single injection of NS-7 significantly improved the neurological symptoms, although the single injection was effective at a higher dose. From these findings, it is suggested that NS-7 reverses the behavioral and cognitive dysfunction observed at the chronic stage of cerebral ischemia by suppressing the cerebral infarction.


Asunto(s)
Conducta Animal/efectos de los fármacos , Infarto Cerebral/tratamiento farmacológico , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Fármacos Neuroprotectores/farmacología , Pirimidinas/farmacología , Animales , Reacción de Prevención/efectos de los fármacos , Bloqueadores de los Canales de Calcio/farmacología , Enfermedad Crónica , Trastornos del Conocimiento/tratamiento farmacológico , Relación Dosis-Respuesta a Droga , Masculino , Ratas , Ratas Sprague-Dawley , Recuperación de la Función/efectos de los fármacos , Bloqueadores de los Canales de Sodio
10.
Brain Res ; 754(1-2): 121-30, 1997 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-9134967

RESUMEN

The effect of a novel cognition enhancer [(+)-5-oxo-D-prolinepiperidinamide monohydrate] (NS-105) on cAMP formation was investigated in both slices and membranes of the rat cerebral cortex. NS-105 (10(-8)-10(-6) M) inhibited forskolin-stimulated cAMP formation in membranes, however, the compound significantly enhanced the cAMP formation in pertussis toxin-pre-treated membranes, an action that was abolished by cholera toxin. In contrast, in digitonin-permeabilized membranes, NS-105 had no influence on Mn2+-stimulated cAMP formation. Both of the inhibitory and facilitatory actions of NS-105 on cAMP formation were mimicked by a metabotropic glutamate receptor (mGluR) agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD) and an adrenergic alpha2 agonist UK-14,304, and blocked by a mGluR antagonist 2-amino-3-phosphonopropanoate but not by an alpha2 antagonist yohimbine. In cortical slices, NS-105 (10(-8)-10(-7) M) inhibited forskolin-stimulated cAMP accumulation but enhanced isoproterenol-stimulated cAMP accumulation, as did by a GABA(B) agonist (-)baclofen. On the other hand, (-)baclofen, while it significantly inhibited cAMP accumulation in slices, did no longer inhibit cAMP accumulation, when treated with NS-105 (10(-8)-10(-5) M). Similarly, (-)baclofen-induced inhibition of the cAMP accumulation was reversed by 1S,3R-ACPD and UK-14,304. NS-105 (10(-6)) increased [35S]GTPgammaS binding in the intact but not digitonin-permeabilized cortical membranes, as produced by UK-14,304, although the compound (10(-9)-10(-3) M) had no influence on various neurotransmitter receptor bindings, including alpha2 receptors. These results suggest that NS-105 modulates adenylate cyclase activity by stimulating mGluRs which might coupled to both Gi/Go and Gs.


Asunto(s)
Adenilil Ciclasas/metabolismo , Corteza Cerebral/metabolismo , Cognición , Proteínas de Unión al GTP/metabolismo , Piperidinas/farmacología , Prolina/análogos & derivados , Receptores de Glutamato Metabotrópico/fisiología , Toxina de Adenilato Ciclasa , Agonistas alfa-Adrenérgicos/farmacología , Alanina/análogos & derivados , Alanina/farmacología , Animales , Baclofeno/farmacología , Tartrato de Brimonidina , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Corteza Cerebral/efectos de los fármacos , Toxina del Cólera/farmacología , Colforsina/farmacología , AMP Cíclico/metabolismo , Cicloleucina/análogos & derivados , Cicloleucina/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Técnicas In Vitro , Isoproterenol/farmacología , Cinética , Masculino , Manganeso/farmacología , Toxina del Pertussis , Prolina/farmacología , Quinoxalinas/farmacología , Ratas , Ratas Wistar , Receptores de Neurotransmisores/efectos de los fármacos , Receptores de Neurotransmisores/fisiología , Factores de Virulencia de Bordetella/farmacología , Yohimbina/farmacología
11.
Brain Res ; 727(1-2): 91-8, 1996 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-8842386

RESUMEN

The effect of flavoxate hydrochloride (flavoxate), an anti-pollakiurea agent, on cyclic AMP (cAMP) formation was investigated in the rat brain and a possible involvement of brain G proteins in the action of flavoxate on the bladder function was subsequently examined. Flavoxate (10(-8)-10(-5) M) inhibited cAMP formation in a concentration-dependent manner, an action which was completely abolished by pretreating the membranes with pertussis toxin (PTX). The inhibitory effect of flavoxate was also completely antagonized by combined treatment with any two antagonists for adenosine A1 (8-cyclopentyl-1,3-dipropylxanthine), dopamine D2 (sulpiride) or adrenergic alpha 2 (yohimbine) receptors, although each antagonist alone did not significantly block the flavoxate-induced inhibition of cAMP formation. Radioligand binding studies indicated that flavoxate at micro- or submicromolar concentrations has affinity for Gi-coupled receptors such as A1, D2 and alpha 2 receptors. Therefore, flavoxate may inhibit cAMP formation by the stimulation of A1, D2 and alpha 2 receptors. To clarify the involvement of brain Gi proteins in the flavoxate-induced inhibition of the micturition reflex, the effect of pretreatment with PTX (i.c.v.) on the flavoxate-induced inhibition of isovolumetric rhythmic bladder contractions was examined in rats. Flavoxate (3 mg/kg, i.v.) completely abolished rhythmic bladder contractions in vehicle-pretreated rats, but not in PTX-pretreated rats. These findings suggest that signal transduction via Gi-coupled receptors is involved, at least in part, in the inhibition of the micturition reflex by flavoxate in rats. These results also provide the first evidence suggesting a negative role of brain PTX-sensitive G proteins in the micturition reflex.


Asunto(s)
Encéfalo/fisiología , Flavoxato/farmacología , Proteínas de Unión al GTP/metabolismo , Toxina del Pertussis , Vejiga Urinaria/fisiología , Micción/efectos de los fármacos , Factores de Virulencia de Bordetella/farmacología , Animales , Encéfalo/efectos de los fármacos , AMP Cíclico/metabolismo , Femenino , Contracción Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Músculo Liso/fisiología , Ratas , Ratas Sprague-Dawley , Receptores Adrenérgicos alfa 2/efectos de los fármacos , Receptores Adrenérgicos alfa 2/fisiología , Receptores de Dopamina D2/efectos de los fármacos , Receptores de Dopamina D2/fisiología , Receptores Muscarínicos/efectos de los fármacos , Receptores Muscarínicos/fisiología , Receptores Purinérgicos P1/efectos de los fármacos , Receptores Purinérgicos P1/fisiología , Reflejo/efectos de los fármacos , Sulpirida/farmacología , Vejiga Urinaria/efectos de los fármacos , Xantinas/farmacología , Yohimbina/farmacología
12.
Eur J Pharmacol ; 387(1): 9-17, 2000 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-10633154

RESUMEN

The involvement of metabotropic glutamate (mGlu) receptors in the modulatory actions of a novel cognition enhancer, (+)-5-oxo-D-prolinepiperidinamide monohydrate (NS-105), on adenylyl cyclase activity in rat cerebrocortical membranes and primary neuronal cultures was investigated using selective antagonists and antisense oligodeoxynucleotides for mGlu receptor subclasses. In rat cerebrocortical membranes, the inhibitory action of NS-105 (0.1 microM) on forskolin-stimulated cAMP formation was blocked by a group II mGlu receptor antagonist, (+/-)-alpha-ethylglutamic acid, and by a group III antagonist, (+)-2-amino-2-methyl-4-phosphonobutanoic acid (MAP-4), but not by a group I antagonist, (+/-)-1-aminoindan-1,5-dicarboxylic acid (AIDA), whereas the facilitation of cAMP formation by NS-105 (1 microM) in pertussis toxin-pretreated membranes was abolished by AIDA but not by (+/-)-alpha-ethylglutamic acid or MAP-4. In primary cultured neurons of mouse cerebral cortex, the inhibitory action of NS-105 on adenylyl cyclase activity disappeared after treatment with antisense oligodeoxynucleotides for group II (mGlu(2) and mGlu(3) receptors) and group III (mGlu(4) and mGlu(7) receptors) but not group I (mGlu(5) receptor) mGlu receptor subclasses. These findings suggest that the inhibitory action of NS-105 on adenylyl cyclase activity is mediated through group II and group III mGlu receptor subclasses while the facilitatory action is dependent on the group I mGlu receptor subclass.


Asunto(s)
Adenilil Ciclasas/metabolismo , Nootrópicos/farmacología , Piperidinas/farmacología , Prolina/análogos & derivados , Receptores de Glutamato Metabotrópico/fisiología , Animales , Benzoatos/farmacología , Células Cultivadas , Corteza Cerebral/citología , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/enzimología , Colforsina/farmacología , AMP Cíclico/metabolismo , Antagonistas de Aminoácidos Excitadores/farmacología , Feto , Regulación de la Expresión Génica , Glicina/análogos & derivados , Glicina/farmacología , Masculino , Membranas/efectos de los fármacos , Membranas/enzimología , Neuronas/citología , Neuronas/metabolismo , Oligodesoxirribonucleótidos Antisentido/genética , Oligodesoxirribonucleótidos Antisentido/farmacología , Oligonucleótidos/genética , Oligonucleótidos/farmacología , Prolina/farmacología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Receptores de Glutamato Metabotrópico/antagonistas & inhibidores , Receptores de Glutamato Metabotrópico/genética
13.
Eur J Pharmacol ; 336(2-3): 283-90, 1997 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-9384244

RESUMEN

The actions of a novel neuroprotective compound, 4-(4-fluorophenyl)-2-methyl-6-(5-piperidinopentyloxy)pyrimidine hydrochloride (NS-7), on voltage-gated Na+, Ca2+ and K+ channels were investigated in a mouse neuroblastoma and rat glioma hybrid cell line, NG108-15, using a whole-cell voltage clamp technique. NG108-15 cells have a tetrodotoxin-sensitive Na+ channel, three types of Ca2+ channel (L, N and T) and voltage-gated K+ channels, all of which were inhibited by NS-7 in a concentration-dependent manner. However, there was a considerable difference in its potency: the IC50 values for the tetrodotoxin-sensitive Na+ channel, L-type Ca2+ channel and N-type Ca2+ channel were similar (7.8, 4.5 and 7.3 microM, respectively), lower than the IC50 value for the T-type Ca2+ channel (17.1 microM), and much lower than the IC50 value for the voltage-gated K+ channel (160.5 microM). NS-7 altered neither the shape nor the reversal potential of the current-voltage curves for Na+, L-type or N-type Ca2+ channels, although the currents were reduced at every potential tested. These results indicate that NS-7 is a Na+ and high-voltage-activated (L- and N-type) Ca2+ channel blocker, and its channel-blocking properties may contribute to its neuroprotective action.


Asunto(s)
Bloqueadores de los Canales de Calcio/farmacología , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Pirimidinas/farmacología , Bloqueadores de los Canales de Sodio , Animales , Ratones , Neuronas/metabolismo , Técnicas de Placa-Clamp , Bloqueadores de los Canales de Potasio , Ratas , Células Tumorales Cultivadas
14.
Eur J Pharmacol ; 338(3): 225-32, 1997 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-9424016

RESUMEN

We have previously found that a cognition enhancer [(+)-5-oxo-D-prolinepiperidinamide monohydrate] (NS-105) reversed the inhibition of cyclic AMP formation induced by the GABA(B) receptor agonist baclofen. The GABA(B) receptor has been implicated in the pathophysiology of depressive illness. The present experiment was designed to evaluate the antidepressant activity of NS-105 in the forced swimming and learned helplessness tests in rats. NS-105 (1-100 mg/kg, p.o.) significantly decreased immobility time in the forced swimming test, an effect similar to that of desipramine. Repeated administration of NS-105 also reversed the failure to escape in the shuttle-box test of rats previously exposed to inescapable footshock. Biochemical data showed that repeated administration of NS-105 increased the number of GABA(B) receptors in rat cerebral cortex without affecting the binding properties of beta-adrenoceptors and 5-HT2 receptors. In contrast to other antidepressants, NS-105 did not inhibit monoamine uptake in vitro, nor did it change monoamine concentrations in brain tissues or extracellular fluids. These findings suggest that NS-105, which lacks an effect on monoaminergic systems, has potent antidepressant activity, which may involve up-regulation of GABA(B) receptors after repeated administration.


Asunto(s)
Antidepresivos/farmacología , Corteza Cerebral/efectos de los fármacos , Trastorno Depresivo/tratamiento farmacológico , Piperidinas/farmacología , Prolina/análogos & derivados , Receptores de GABA-B/metabolismo , Animales , Corteza Cerebral/metabolismo , Masculino , Microdiálisis , Norepinefrina/metabolismo , Prolina/farmacología , Ratas , Ratas Wistar , Receptores Adrenérgicos beta/metabolismo , Receptores de Serotonina/metabolismo , Serotonina/metabolismo , Sinaptosomas/metabolismo
15.
Eur J Pharmacol ; 415(2-3): 209-16, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11275001

RESUMEN

Mechanisms underlying celiprolol-induced vasodilatation were analyzed in isolated porcine coronary arteries. Celiprolol induced dose-related relaxation of the artery rings with endothelium, an effect which was suppressed by N(G)-nitro-L-arginine methylester (L-NAME), nitric oxide (NO) scavenger, guanylate cyclase inhibitor, endothelium denudation, and removal of Ca(2+). L-NAME contracted, and superoxide dismutase relaxed, the arteries only when the endothelium was preserved. Neither superoxide dismutase nor beta-adrenoceptor antagonists changed celiprolol-induced relaxations. Celiprolol increased the cyclic GMP content in the tissue. The release of NO from endothelium, estimated by the extracellular production of cyclic GMP in arteries incubated in medium containing guanylate cyclase and GTP, was augmented by celiprolol, and L-NAME abolished this action of celiprolol. It is concluded that celiprolol elicits relaxation by acting on sites other than beta-adrenoceptors in the endothelium and by releasing NO, which activates soluble guanylate cyclase in smooth muscle and produces cyclic GMP. Scavenging of superoxide anions from the endothelium does not seem to account for the induced relaxation.


Asunto(s)
Antagonistas de Receptores Adrenérgicos beta 1 , Antagonistas Adrenérgicos beta/farmacología , Celiprolol/farmacología , Vasos Coronarios/efectos de los fármacos , Óxido Nítrico Sintasa/efectos de los fármacos , Vasodilatación/efectos de los fármacos , Animales , Vasos Coronarios/metabolismo , GMP Cíclico/metabolismo , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/farmacología , Depuradores de Radicales Libres/farmacología , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico Sintasa de Tipo III , Superóxido Dismutasa/farmacología , Porcinos , Vasodilatación/fisiología
16.
Eur J Pharmacol ; 318(1): 117-22, 1996 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-9007522

RESUMEN

The effects of NS-49 ((R)-(-)-3'-(2-amino-1-hydroxyethyl)-4'-fluoromethane sulfonanilide hydrochloride), an alpha 1A-adrenoceptor-selective agonist, on intraurethral pressure and blood pressure were investigated in anesthetized dogs. In addition, the contractile effects of NS-49 on the isolated dog urethra and carotid artery were compared with those of non-selective alpha 1-adrenoceptor agonists. Intravenously (i.v.) administered NS-49 at 0.3 microgram/kg or more significantly increased intraurethral pressure in a dose-dependent manner. Much higher doses of NS-49 were needed to increase blood pressure. In contrast, ST-1059 (1-(2',5'-dimethoxyphenyl)-2-aminoethanol) (an active metabolite of midodrine) at 30 micrograms/kg or more significantly increased both intraurethral pressure and blood pressure. NS-49 was 11-fold more selective for intraurethral pressure than ST-1059, NS-49, ST-1059, phenylephrine and noradrenaline caused concentration-dependent contraction of the isolated dog urethra. NS-49 caused only a slight contraction of the dog carotid artery even at high concentrations, whereas the reference drugs caused contractions of the artery with high efficacy. The alpha 1A-adrenoceptor-selective antagonists 5-methyl-urapidil and WB-4101 also showed high affinity for alpha 1-adrenoceptors in the dog urethra in inhibiting [3H]prazosin binding. In conclusion, the alpha 1A-selective agonist NS-49 selectively increased intraurethral pressure in dogs, and produced selective contraction of the dog urethra. These results suggest that the alpha 1A-adrenoceptor subtype is responsible for the contraction of the urethra and the regulation of intraurethral pressure, and that NS-49 might be useful for the treatment of stress incontinence with little effect on the cardiovascular system.


Asunto(s)
Agonistas alfa-Adrenérgicos/farmacología , Anilidas/farmacología , Músculo Liso/efectos de los fármacos , Receptores Adrenérgicos alfa 1/fisiología , Uretra/efectos de los fármacos , Animales , Presión Sanguínea/efectos de los fármacos , Arterias Carótidas/efectos de los fármacos , Perros , Relación Dosis-Respuesta a Droga , Femenino , Técnicas In Vitro , Hígado/metabolismo , Masculino , Midodrina/análogos & derivados , Midodrina/farmacología , Contracción Muscular/efectos de los fármacos , Músculo Liso/fisiología , Músculo Liso Vascular/efectos de los fármacos , Prazosina/farmacología , Presión , Ratas , Ratas Sprague-Dawley , Receptores Adrenérgicos alfa 1/metabolismo , Glándula Submandibular/metabolismo , Uretra/fisiología
17.
Neurosci Lett ; 252(3): 203-6, 1998 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-9739996

RESUMEN

The spontaneous dopamine release from rat striatum, measured by intracerebral microdialysis, was markedly reduced by local perfusion of tetrodotoxin (1 microM) through the dialysis probe. In addition, striatal microinjection of omega-conotoxin GVIA (10 pmol) or omega-agatoxin i.v.A (1 pmol), but not local perfusion of nimodipine, suppressed the spontaneous dopamine release. Therefore, the spontaneous dopamine release may depend on the activity of both Na+ channel as well as N-type and P/Q-type Ca2+ channels. In contrast, local perfusion of a novel Na+- and Ca2+-channel blocker NS-7 (10 microM) did not affect spontaneous dopamine release, whereas it markedly blocked KCl- and veratridine-evoked dopamine release. Therefore, NS-7 may block Na+- and Ca2+-channels only when the ion channels are highly activated.


Asunto(s)
Bloqueadores de los Canales de Calcio/farmacología , Cuerpo Estriado/efectos de los fármacos , Dopamina/metabolismo , Fármacos Neuroprotectores/farmacología , Pirimidinas/farmacología , Bloqueadores de los Canales de Sodio , Animales , Cuerpo Estriado/metabolismo , Evaluación Preclínica de Medicamentos , Masculino , Microdiálisis , Microinyecciones , Nimodipina/farmacología , Péptidos/farmacología , Ratas , Ratas Sprague-Dawley , Venenos de Araña/farmacología , Tetrodotoxina/farmacología , omega-Agatoxina IVA , omega-Conotoxina GVIA
18.
Neurosci Lett ; 195(3): 214-6, 1995 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-8584213

RESUMEN

An inhibitory influence from the nucleus reticularis pontis oralis on the micturition induced by electrical stimulation of the pontine micturition center was investigated in decerebrate cats at the supracollicular level. Monopolar electrical stimulation (30-50 microA, 0.2 ms, 50 Hz, 3 s) of the nucleus locus coeruleus alpha (pontine micturition center) produced micturition similar to that induced by distending the bladder by saline infusion. The intravesical pressure increase and micturition induced by electrical stimulation of the nucleus locus coeruleus alpha were suppressed by electrical stimulation of the nucleus reticularis pontis oralis in the intensity range 20-100 microA in a stimulus-intensity-dependent manner. These findings indicate that the nucleus reticularis pontis oralis has an inhibitory influence on the functions of the micturition center.


Asunto(s)
Gatos/fisiología , Inhibición Neural/fisiología , Puente/fisiología , Micción/fisiología , Animales , Estado de Descerebración/fisiopatología , Estimulación Eléctrica , Locus Coeruleus/fisiología , Vejiga Urinaria/inervación
19.
Neurosci Lett ; 305(3): 193-6, 2001 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-11403938

RESUMEN

The effect of a neuroprotective agent NS-7 on changes in mRNA expressions for cyclic AMP responsive element binding protein (CREB) and several neurotrophins was examined in the rat cerebral cortex after permanent middle cerebral artery occlusion (MCAO). Significant reduction in mRNA expressions for CREB was observed at 24h after MCAO. NS-7 (0.5mg/kg), when injected at 6h after MCAO, significantly reversed the decreased expression for CREB mRNA. In addition, the mRNA expression for basic fibroblast growth factor (bFGF) was also significantly enhanced by NS-7 in MCA-occluded but not in sham-operated rats. On the other hand, the mRNAs for interluekin-6 and inducible-type nitric oxide synthase were markedly induced in the cerebral cortex of MCA-occluded rats, which was not significantly reversed by NS-7. Therefore, it is suggested that the reversal of decrease in CREB mRNA and concomitant increase in mRNA expression for bFGF may contribute to the neuroprotective action of NS-7.


Asunto(s)
Arteriopatías Oclusivas/metabolismo , Encéfalo/metabolismo , Arterias Cerebrales , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/genética , Fármacos Neuroprotectores/farmacología , Pirimidinas/farmacología , ARN Mensajero/metabolismo , Animales , Factor Neurotrófico Derivado del Encéfalo/genética , Factor 2 de Crecimiento de Fibroblastos/genética , Masculino , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Ratas , Ratas Sprague-Dawley
20.
Neurosci Lett ; 16(3): 319-22, 1980 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7052447

RESUMEN

The effects of a new endogenous opioid dipeptide (Tyr-Arg), kyotorphin, on single unit activities recorded from the lamina V type neurons in the spinal dorsal horn and the neurons in nucleus reticularis paragigantocellularis (NRPG) of the medulla oblongata were investigated in the rabbit and rat, respectively. Microelectrophoretically applied kyotorphin predominantly depressed the lamina V type neurons but excited the NRPG neurons. Such predominant effects were antagonized by naloxone. These results suggest that kyotorphin has qualitatively similar actions to those of enkephalins in both central regions examined.


Asunto(s)
Endorfinas/farmacología , Bulbo Raquídeo/efectos de los fármacos , Médula Espinal/efectos de los fármacos , Animales , Endorfinas/antagonistas & inhibidores , Cobayas , Iontoforesis , Masculino , Microinyecciones , Naloxona/farmacología , Conejos , Ratas , Ratas Endogámicas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA