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Pesquisa : B01.050.150.900.090.180.708.240 [Categoria DeCS]
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[PMID]:29191658
[Au] Autor:Sang M; Wu Q; Xi X; Ma C; Wang L; Zhou M; Burrows JF; Chen T
[Ad] Endereço:School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, China; School of Pharmacy, Queen's University, Belfast BT9 7BL, Northern Ireland, UK.
[Ti] Título:Identification and target-modifications of temporin-PE: A novel antimicrobial peptide in the defensive skin secretions of the edible frog, Pelophylax kl. esculentus.
[So] Source:Biochem Biophys Res Commun;495(4):2539-2546, 2018 01 22.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:A potent natural antimicrobial peptide named temporin-PE was identified and encoded from the skin secretions of Pelophylax kl. esculentus via "shotgun" cloning and LC-MS/MS fragmentation analysis. Target-modifications were carried out to further enhance the antimicrobial and anti-proliferative bioactivities, whilst decreasing the hemolytic effect. A range of bioassays demonstrated that replacing a proline with a tyrosine residue resulted in a loss of the bioactivity against Gram-negative bacteria, but dramatically improved the hemolytic and anti-proliferative activity, indicating the FLP- motif influences the hemolytic activity of temporins. Moreover, the coupling of TAT to the peptide dramatically improved its antimicrobial activity, indicating coupling TAT to these peptides could be considered as a potential tool to improve their antimicrobial activity. Overall, we have shown that targeted modifications of this natural antimicrobial peptide can adjust its bioactivities to help its development as an antibiotic or anti-proliferative agent.
[Mh] Termos MeSH primário: Proteínas de Anfíbios/química
Peptídeos Catiônicos Antimicrobianos/administração & dosagem
Peptídeos Catiônicos Antimicrobianos/química
Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos
Rana esculenta/metabolismo
Pele/secreção
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Proteínas de Anfíbios/administração & dosagem
Proteínas de Anfíbios/secreção
Animais
Antibacterianos/administração & dosagem
Antibacterianos/química
Antibacterianos/isolamento & purificação
Peptídeos Catiônicos Antimicrobianos/secreção
Sobrevivência Celular/efeitos dos fármacos
Dados de Sequência Molecular
Pele/microbiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Amphibian Proteins); 0 (Anti-Bacterial Agents); 0 (Antimicrobial Cationic Peptides); 0 (temporin-PE, Pelophylax kl. esculentus)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180222
[Lr] Data última revisão:
180222
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171202
[St] Status:MEDLINE


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[PMID]:28859158
[Au] Autor:Kanaporis G; Treinys R; Fischmeister R; Jurevicius J
[Ad] Endereço:Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania.
[Ti] Título:Metabolic inhibition reduces cardiac L-type Ca2+ channel current due to acidification caused by ATP hydrolysis.
[So] Source:PLoS One;12(8):e0184246, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Metabolic stress evoked by myocardial ischemia leads to impairment of cardiac excitation and contractility. We studied the mechanisms by which metabolic inhibition affects the activity of L-type Ca2+ channels (LTCCs) in frog ventricular myocytes. Metabolic inhibition induced by the protonophore FCCP (as well as by 2,4- dinitrophenol, sodium azide or antimycin A) resulted in a dose-dependent reduction of LTCC current (ICa,L) which was more pronounced during ß-adrenergic stimulation with isoprenaline. ICa,L was still reduced by metabolic inhibition even in the presence of 3 mM intracellular ATP, or when the cell was dialysed with cAMP or ATP-γ-S to induce irreversible thiophosphorylation of LTCCs, indicating that reduction in ICa,L is not due to ATP depletion and/or reduced phosphorylation of the channels. However, the effect of metabolic inhibition on ICa,L was strongly attenuated when the mitochondrial F1F0-ATP-synthase was blocked by oligomycin or when the cells were dialysed with the non-hydrolysable ATP analogue AMP-PCP. Moreover, increasing the intracellular pH buffering capacity or intracellular dialysis of the myocytes with an alkaline solution strongly attenuated the inhibitory effect of FCCP on ICa,L. Thus, our data demonstrate that metabolic inhibition leads to excessive ATP hydrolysis by the mitochondrial F1F0-ATP-synthase operating in the reverse mode and this results in intracellular acidosis causing the suppression of ICa,L. Limiting ATP break-down by F1F0-ATP-synthase and the consecutive development of intracellular acidosis might thus represent a potential therapeutic approach for maintaining a normal cardiac function during ischemia.
[Mh] Termos MeSH primário: Canais de Cálcio Tipo L/metabolismo
ATPases Mitocondriais Próton-Translocadoras/metabolismo
Contração Miocárdica/genética
Isquemia Miocárdica/metabolismo
[Mh] Termos MeSH secundário: Trifosfato de Adenosina/metabolismo
Animais
Canais de Cálcio Tipo L/genética
Carbonil Cianeto p-Trifluormetoxifenil Hidrazona/administração & dosagem
Ventrículos do Coração/metabolismo
Ventrículos do Coração/fisiopatologia
Isoproterenol/administração & dosagem
Mitocôndrias/enzimologia
Células Musculares/efeitos dos fármacos
Células Musculares/metabolismo
Contração Miocárdica/efeitos dos fármacos
Isquemia Miocárdica/genética
Isquemia Miocárdica/fisiopatologia
Miócitos Cardíacos/efeitos dos fármacos
Miócitos Cardíacos/metabolismo
Miócitos Cardíacos/patologia
Rana esculenta
Estresse Fisiológico/efeitos dos fármacos
Estresse Fisiológico/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Calcium Channels, L-Type); 370-86-5 (Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone); 8L70Q75FXE (Adenosine Triphosphate); EC 3.6.1.- (F1F0-ATP synthase); EC 3.6.3.- (Mitochondrial Proton-Translocating ATPases); L628TT009W (Isoproterenol)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171011
[Lr] Data última revisão:
171011
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170901
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0184246


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[PMID]:27629268
[Au] Autor:Prokic MD; Borkovic-Mitic SS; Krizmanic II; Mutic JJ; Trifkovic JD; Gavric JP; Despotovic SG; Gavrilovic BR; Radovanovic TB; Pavlovic SZ; Saicic ZS
[Ad] Endereço:Department of Physiology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Bulevar despota Stefana 142, Belgrade, 11060, Serbia. marko.prokic@ibiss.bg.ac.rs.
[Ti] Título:Bioaccumulation and effects of metals on oxidative stress and neurotoxicity parameters in the frogs from the Pelophylax esculentus complex.
[So] Source:Ecotoxicology;25(8):1531-1542, 2016 Oct.
[Is] ISSN:1573-3017
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Metals are involved in the formation of reactive oxygen species and can induce oxidative stress. The aim of this study was to assess the effects of several metals on oxidative stress in the skin and muscle of the Pelophylax esculentus "complex" frogs (parental species Pelophylax ridibundus, Pelophylax lessonae, and their hybrid Pelophylax esculentus) that inhabit the wetland Obedska Bara in Serbia, and the potential use of these species as bioindicator organisms in biomonitoring studies. The biomarkers of oxidative stress (SOD, CAT, GSH-Px, GR, GST activities and GSH, SH concentrations) and cholinesterase activity were investigated. The concentrations of nine metals (Fe, Cu, Zn, As, Cd, Cr, Hg, Ni, and Pb) were measured in the water and tissues. Correlations were established between metals and biomarkers in the tissues. The results of metal accumulation distinguished the skin of P. lessonae and muscle of P. ridibundus from other P. esculentus complex species. The oxidative stress biomarkers observed in P. ridibundus and P. esculentus had greater similarity than in P. lessonae. The P. lessonae displayed the highest number of correlations between biomarkers and metals. The results of tissue responses revealed that skin was more susceptible to metal-induced oxidative stress, with only exception of As. In the light of these findings, we can suggest the use of P. esculentus complex species as a biomonitoring species in studies of metal accumulation and metal-induced oxidative stress, but with special emphasis on P. lessonae.
[Mh] Termos MeSH primário: Monitoramento Ambiental
Estresse Oxidativo/fisiologia
Rana esculenta/fisiologia
Poluentes Químicos da Água/metabolismo
[Mh] Termos MeSH secundário: Animais
Metais/análise
Metais/metabolismo
Metais/toxicidade
Músculos/metabolismo
Sérvia
Pele/metabolismo
Poluentes Químicos da Água/análise
Poluentes Químicos da Água/toxicidade
Zonas Úmidas
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Metals); 0 (Water Pollutants, Chemical)
[Em] Mês de entrada:1701
[Cu] Atualização por classe:171019
[Lr] Data última revisão:
171019
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160916
[St] Status:MEDLINE


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[PMID]:27402449
[Au] Autor:Chen X; Wang H; Wang L; Zhou M; Chen T; Shaw C
[Ad] Endereço:School of Pharmacy, Fujian Medical University, Fuzhou, Fujian, China. leochen5139@fjmu.edu.cn.
[Ti] Título:Identification of Miscellaneous Peptides from the Skin Secretion of the European Edible Frog, Pelophylax kl. Esculentus.
[So] Source:Protein J;35(4):291-9, 2016 08.
[Is] ISSN:1875-8355
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:The chemical compounds synthesised and secreted from the dermal glands of amphibian have diverse bioactivities that play key roles in the hosts' innate immune system and in causing diverse pharmacological effects in predators that may ingest the defensive skin secretions. As new biotechnological methods have developed, increasing numbers of novel peptides with novel activities have been discovered from this source of natural compounds. In this study, a number of defensive skin secretion peptide sequences were obtained from the European edible frog, P. kl. esculentus, using a 'shotgun' cloning technique developed previously within our laboratory. Some of these sequences have been previously reported but had either obtained from other species or were isolated using different methods. Two new skin peptides are described here for the first time. Esculentin-2c and Brevinin-2Tbe belong to the Esculentin-2 and Brevinin-2 families, respectively, and both are very similar to their respective analogues but with a few amino acid differences. Further, [Asn-3, Lys-6, Phe-13] 3-14-bombesin isolated previously from the skin of the marsh frog, Rana ridibunda, was identified here in the skin of P. kl. esculentus. Studies such as this can provide a rapid elucidation of peptide and corresponding DNA sequences from unstudied species of frogs and can rapidly provide a basis for related scientific studies such as those involved in systematic or the evolution of a large diverse gene family and usage by biomedical researchers as a source of potential novel drug leads or pharmacological agents.
[Mh] Termos MeSH primário: Proteínas de Anfíbios/isolamento & purificação
Peptídeos Catiônicos Antimicrobianos/isolamento & purificação
Bombesina/isolamento & purificação
Rana esculenta/metabolismo
Pele/química
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Proteínas de Anfíbios/biossíntese
Proteínas de Anfíbios/genética
Animais
Peptídeos Catiônicos Antimicrobianos/biossíntese
Peptídeos Catiônicos Antimicrobianos/genética
Sequência de Bases
Bombesina/análogos & derivados
Bombesina/biossíntese
Bombesina/genética
Clonagem Molecular
Escherichia coli/genética
Escherichia coli/metabolismo
Expressão Gênica
Isoformas de Proteínas/biossíntese
Isoformas de Proteínas/genética
Isoformas de Proteínas/isolamento & purificação
Proteínas Recombinantes/biossíntese
Proteínas Recombinantes/genética
Proteínas Recombinantes/isolamento & purificação
Alinhamento de Sequência
Análise de Sequência de DNA
Pele/secreção
Espectrometria de Massas em Tandem
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Amphibian Proteins); 0 (Antimicrobial Cationic Peptides); 0 (Protein Isoforms); 0 (Recombinant Proteins); 0 (esculentin protein, Rana esculenta); 145963-50-4 (brevinin-2, Rana); PX9AZU7QPK (Bombesin)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:171027
[Lr] Data última revisão:
171027
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160713
[St] Status:MEDLINE
[do] DOI:10.1007/s10930-016-9672-z


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[PMID]:27082722
[Au] Autor:Hermaniuk A; Rybacki M; Taylor JR
[Ti] Título:Low Temperature and Polyploidy Result in Larger Cell and Body Size in an Ectothermic Vertebrate.
[So] Source:Physiol Biochem Zool;89(2):118-29, 2016 Mar-Apr.
[Is] ISSN:1537-5293
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Previous studies reported that low temperatures result in increases in both cell size and body size in ectotherms that may explain patterns of geographic variation of their body size across latitudinal ranges. Also, polyploidy showed the same effect on body size in invertebrates. In vertebrates, despite their having larger cells, no clear effect of polyploidy on body size has been found. This article presents the relationship between temperature, cell size, growth rate, and body size in diploid and polyploid hybridogenetic frog Pelophylax esculentus reared as tadpoles at 19° and 24°C. The size of cells was larger in both diploid and triploid tadpoles at 19°C, and triploids had larger cells at both temperatures. In diploid and triploid froglets, the temperature in which they developed as tadpoles did not affect the size of their cells, but triploids still had larger cells. Triploid tadpoles grew faster than diploids at 19°C and had larger body mass; there was no clear difference between ploidies in growth rate at 24°C. This indicates better adaptation of triploid tadpoles to cold environment. This is the first report on the increase of body mass of a polyploid vertebrate caused by low temperature, and we showed relationship between increase in cell size and increased body mass. The large body mass of triploids may provide a selective advantage, especially in colder environments, and this may explain the prevalence of triploids in the northern parts of the geographic range of P. esculentus.
[Mh] Termos MeSH primário: Peso Corporal/fisiologia
Temperatura Baixa
Diploide
Rana esculenta/crescimento & desenvolvimento
Triploidia
[Mh] Termos MeSH secundário: Animais
Peso Corporal/genética
Tamanho Celular
Larva/genética
Larva/crescimento & desenvolvimento
Rana esculenta/genética
Rana esculenta/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Em] Mês de entrada:1701
[Cu] Atualização por classe:170104
[Lr] Data última revisão:
170104
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160416
[St] Status:MEDLINE
[do] DOI:10.1086/684974


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[PMID]:26676115
[Au] Autor:Treinys R; Bogdelis A; Rimkute L; Jurevicius J; Skeberdis VA
[Ad] Endereço:Institute of Cardiology, Lithuanian University of Health Sciences, Sukileliu pr. 17, 50009, Kaunas, Lithuania.
[Ti] Título:Differences in the control of basal L-type Ca(2+) current by the cyclic AMP signaling cascade in frog, rat, and human cardiac myocytes.
[So] Source:J Physiol Sci;66(4):327-36, 2016 Jul.
[Is] ISSN:1880-6562
[Cp] País de publicação:Japan
[La] Idioma:eng
[Ab] Resumo:ß-adrenergic receptors (ß-ARs) mediate the positive inotropic effects of catecholamines by cAMP-dependent phosphorylation of the L-type Ca(2+) channels (LTCCs), which provide Ca(2+) for the initiation and regulation of cell contraction. The overall effect of cAMP-modulating agents on cardiac calcium current (I Ca,L) and contraction depends on the basal activity of LTCCs which, in turn, depends on the basal activities of key enzymes involved in the cAMP signaling cascade. Our current work is a comparative study demonstrating the differences in the basal activities of ß-ARs, adenylyl cyclase, phosphodiesterases, phosphatases, and LTCCs in the frog and rat ventricular and human atrial myocytes. The main conclusion is that the basal I Ca,L, and consequently the contractile function of the heart, is secured from unnecessary elevation of its activity and energy consumption at the several "checking-points" of cAMP-dependent signaling cascade and the loading of these "checking-points" may vary in different species and tissues.
[Mh] Termos MeSH primário: Canais de Cálcio Tipo L/metabolismo
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo
AMP Cíclico/metabolismo
Miócitos Cardíacos/metabolismo
Receptores Adrenérgicos beta/metabolismo
Transdução de Sinais/fisiologia
[Mh] Termos MeSH secundário: Animais
Feminino
Seres Humanos
Masculino
Miocárdio/metabolismo
Técnicas de Patch-Clamp
Fosforilação
Rana esculenta
Ratos
Ratos Wistar
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Calcium Channels, L-Type); 0 (Receptors, Adrenergic, beta); E0399OZS9N (Cyclic AMP); EC 2.7.11.11 (Cyclic AMP-Dependent Protein Kinases)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:171110
[Lr] Data última revisão:
171110
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151218
[St] Status:MEDLINE
[do] DOI:10.1007/s12576-015-0430-3


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[PMID]:26586207
[Au] Autor:Ciaramella V; Meccariello R; Chioccarelli T; Sirleto M; Fasano S; Pierantoni R; Chianese R
[Ad] Endereço:Dipartimento di Medicina Sperimentale sez "F. Bottazzi", Seconda Università di Napoli, Via Costantinopoli 16, 80138 Napoli, Italy. Electronic address: enza.ciaramella@unina2.it.
[Ti] Título:Anandamide acts via kisspeptin in the regulation of testicular activity of the frog, Pelophylax esculentus.
[So] Source:Mol Cell Endocrinol;420:75-84, 2016 Jan 15.
[Is] ISSN:1872-8057
[Cp] País de publicação:Ireland
[La] Idioma:eng
[Ab] Resumo:In the frog Pelophylax esculentus, the endocannabinoid anandamide (AEA) modulates Gonadotropin Releasing Hormone (GnRH) system in vitro and down-regulates steroidogenic enzymes in vivo. Thus, male frogs were injected with AEA ± SR141716A, a cannabinoid receptor 1 (CB1) antagonist, to evaluate possible effects on GnRH and Kiss1/Gpr54 systems, gonadotropin receptors and steroid levels. In frog diencephalons, AEA negatively affected both GnRH and Kiss1/Gpr54 systems. In testis, AEA induced the expression of gonadotropin receptors, cb1, gnrh2 and gnrhr3 meanwhile reducing gnrhr2 mRNA and Kiss1/Gpr54 proteins. Furthermore, aromatase (Cyp19) expression increased in parallel to testosterone decrease and estradiol increase. In vitro treatment of testis with AEA revealed direct effects on Cyp19 and induced the expression of the AEA-degrading enzyme Faah. Lastly, AEA effects on Faah were counteracted by the antiestrogen ICI182780, indicating estradiol mediated effect. In conclusion, for the first time we show in a vertebrate that AEA regulates testicular activity through kisspeptin system.
[Mh] Termos MeSH primário: Ácidos Araquidônicos/farmacologia
Endocanabinoides/farmacologia
Kisspeptinas/metabolismo
Alcamidas Poli-Insaturadas/farmacologia
Rana esculenta/metabolismo
Testículo/metabolismo
[Mh] Termos MeSH secundário: Amidoidrolases/metabolismo
Animais
Aromatase/metabolismo
Diencéfalo/efeitos dos fármacos
Diencéfalo/metabolismo
Estradiol/metabolismo
Masculino
Piperidinas/farmacologia
Pirazóis/farmacologia
Receptores da Gonadotropina/metabolismo
Testosterona/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Arachidonic Acids); 0 (Endocannabinoids); 0 (Kisspeptins); 0 (Piperidines); 0 (Polyunsaturated Alkamides); 0 (Pyrazoles); 0 (Receptors, Gonadotropin); 3XMK78S47O (Testosterone); 4TI98Z838E (Estradiol); EC 1.14.14.1 (Aromatase); EC 3.5.- (Amidohydrolases); EC 3.5.1.- (fatty-acid amide hydrolase); RML78EN3XE (rimonabant); UR5G69TJKH (anandamide)
[Em] Mês de entrada:1609
[Cu] Atualização por classe:161126
[Lr] Data última revisão:
161126
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151121
[St] Status:MEDLINE


  8 / 3088 MEDLINE  
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[PMID]:26444079
[Au] Autor:Kovalecz G; Kecskes S; Birinyi A; Matesz C
[Ad] Endereço:Department of Pediatric Dentistry and Orthodontics, Faculty of Dentistry, University of Debrecen, Nagyerdei krt. 98, Debrecen H-4032, Hungary.
[Ti] Título:Possible neural network mediating jaw opening during prey-catching behavior of the frog.
[So] Source:Brain Res Bull;119(Pt A):19-24, 2015 Oct.
[Is] ISSN:1873-2747
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The prey-catching behavior of the frog is a complex, well-timed sequence of stimulus response chain of movements. After visual analysis of the prey, a size dependent program is selected in the motor pattern generator of the brainstem. Besides this predetermined feeding program, various direct and indirect sensory inputs provide flexible adjustment for the optimal contraction of the executive muscles. The aim of the present study was to investigate whether trigeminal primary afferents establish direct contacts with the jaw opening motoneurons innervated by the facial nerve. The experiments were carried out on Rana esculenta (Pelophylax esculentus), where the trigeminal and facial nerves were labeled simultaneously with different fluorescent dyes. Using a confocal laser scanning microscope, close appositions were detected between trigeminal afferent fibers and somatodendritic components of the facial motoneurons. Quantitative analysis revealed that the majority of close contacts were encountered on the dendrites of facial motoneurons and approximately 10% of them were located on the perikarya. We suggest that the identified contacts between the trigeminal afferents and facial motoneurons presented here may be one of the morphological substrate in the feedback and feedforward modulation of the rapidly changing activity of the jaw opening muscle during the prey-catching behavior.
[Mh] Termos MeSH primário: Nervo Facial/citologia
Neurônios Motores/citologia
Neurônios Aferentes/citologia
Comportamento Predatório/fisiologia
Rana esculenta/anatomia & histologia
Núcleos do Trigêmeo/citologia
[Mh] Termos MeSH secundário: Vias Aferentes/citologia
Vias Aferentes/fisiologia
Animais
Dendritos
Nervo Facial/fisiologia
Arcada Osseodentária/anatomia & histologia
Arcada Osseodentária/fisiologia
Microscopia Confocal
Neurônios Motores/fisiologia
Neurônios Aferentes/fisiologia
Fotomicrografia
Rana esculenta/fisiologia
Núcleos do Trigêmeo/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Em] Mês de entrada:1608
[Cu] Atualização por classe:151120
[Lr] Data última revisão:
151120
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151008
[St] Status:MEDLINE


  9 / 3088 MEDLINE  
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[PMID]:26141702
[Au] Autor:Reyer HU; Arioli-Jakob C; Arioli M
[Ad] Endereço:Institute of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, Zürich, CH-8057, Switzerland. uli.reyer@ieu.uzh.ch.
[Ti] Título:Post-zygotic selection against parental genotypes during larval development maintains all-hybrid populations of the frog Pelophylax esculentus.
[So] Source:BMC Evol Biol;15:131, 2015 Jul 04.
[Is] ISSN:1471-2148
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Hybridization between two species usually leads to inviable or infertile offspring, due to endogenous or exogenous selection pressures. Yet, hybrid taxa are found in several plant and animal genera, and some of these hybrid taxa are ecologically and evolutionarily very successful. One example of such a successful hybrid is the water frog, Pelophylax esculentus which originated from matings between the two species P. ridibundus (genotype RR) and P. lessonae (LL). At the northern border of the distribution all-hybrid populations consisting of diploid (LR) and one or two triploid (LLR, LRR) frog types have been established. Here, the hybrid has achieved reproductive independence from its sexual ancestors and forms a self-sustaining evolutionary unit. Based on the gamete production of these hybrids, certain mating combinations should lead to LL and RR offspring, but these parental forms are absent among the adults. RESULTS: In order to investigate the mechanisms that maintain such an all-hybrid system, we performed a field study and a crossing experiment. In the field we sampled several ponds for water frog larvae at different developmental stages. Genotype compositions were then analysed and life-history differences between the genotypes examined. In the experiment we crossed diploid and triploid males and females from different ponds and determined fertilization success as well as development speed and survival rates of the offspring under high, medium and low food availability. In both parts of the study, we found numerous LL and RR offspring during the egg and early larval stages; but the frequency of these parental genotypes decreased drastically during later stages. In natural ponds almost all of them had disappeared already before metamorphosis; under the more benign experimental conditions the last ones died as juveniles during the following year. CONCLUSIONS: From the combined results we conclude that the absence of parental genotypes in all-hybrid populations is due to post-zygotic selection against them, rather than to pre-zygotic mechanisms that might prevent their formation in the first place. For this post-zygotic selection, genetic mechanisms resulting from low genetic diversity and fixation of deleterious mutations seem to be a more likely explanation than ecological factors.
[Mh] Termos MeSH primário: Rana esculenta/crescimento & desenvolvimento
Rana esculenta/genética
[Mh] Termos MeSH secundário: Animais
Feminino
Citometria de Fluxo
Variação Genética
Hibridização Genética
Masculino
Metamorfose Biológica
Repetições de Microssatélites
Ploidias
Ranidae/genética
Ranidae/crescimento & desenvolvimento
Reprodução
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Em] Mês de entrada:1511
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150705
[St] Status:MEDLINE
[do] DOI:10.1186/s12862-015-0404-3


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[PMID]:25785994
[Au] Autor:do Rego JL; Vaudry D; Vaudry H
[Ad] Endereço:Institute for Research and Innovation in Biomedicine (IRIB), University of Rouen, Mont-Saint-Aignan, France; Regional Platform for Cell Imaging (PRIMACEN), International Associated Laboratory Samuel de Champlain, University of Rouen, Mont-Saint-Aignan, France.
[Ti] Título:The non-benzodiazepine anxiolytic drug etifoxine causes a rapid, receptor-independent stimulation of neurosteroid biosynthesis.
[So] Source:PLoS One;10(3):e0120473, 2015.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Neurosteroids can modulate the activity of the GABAA receptors, and thus affect anxiety-like behaviors. The non-benzodiazepine anxiolytic compound etifoxine has been shown to increase neurosteroid concentrations in brain tissue but the mode of action of etifoxine on neurosteroid formation has not yet been elucidated. In the present study, we have thus investigated the effect and the mechanism of action of etifoxine on neurosteroid biosynthesis using the frog hypothalamus as an experimental model. Exposure of frog hypothalamic explants to graded concentrations of etifoxine produced a dose-dependent increase in the biosynthesis of 17-hydroxypregnenolone, dehydroepiandrosterone, progesterone and tetrahydroprogesterone, associated with a decrease in the production of dihydroprogesterone. Time-course experiments revealed that a 15-min incubation of hypothalamic explants with etifoxine was sufficient to induce a robust increase in neurosteroid synthesis, suggesting that etifoxine activates steroidogenic enzymes at a post-translational level. Etifoxine-evoked neurosteroid biosynthesis was not affected by the central-type benzodiazepine (CBR) receptor antagonist flumazenil, the translocator protein (TSPO) antagonist PK11195 or the GABAA receptor antagonist bicuculline. In addition, the stimulatory effects of etifoxine and the triakontatetraneuropeptide TTN, a TSPO agonist, were additive, indicating that these two compounds act through distinct mechanisms. Etifoxine also induced a rapid stimulation of neurosteroid biosynthesis from frog hypothalamus homogenates, a preparation in which membrane receptor signalling is disrupted. In conclusion, the present study demonstrates that etifoxine stimulates neurosteroid production through a membrane receptor-independent mechanism.
[Mh] Termos MeSH primário: 17-alfa-Hidroxipregnenolona/agonistas
Ansiolíticos/farmacologia
Desidroepiandrosterona/agonistas
Hipotálamo/efeitos dos fármacos
Oxazinas/farmacologia
Pregnanolona/agonistas
Progesterona/agonistas
[Mh] Termos MeSH secundário: 17-alfa-Hidroxipregnenolona/metabolismo
20-alfa-Di-Hidroprogesterona/antagonistas & inibidores
20-alfa-Di-Hidroprogesterona/biossíntese
Animais
Bicuculina/farmacologia
Misturas Complexas/química
Desidroepiandrosterona/biossíntese
Relação Dose-Resposta a Droga
Flumazenil/farmacologia
Moduladores GABAérgicos/farmacologia
Antagonistas de Receptores de GABA-A/farmacologia
Expressão Gênica
Hipotálamo/metabolismo
Isoquinolinas/farmacologia
Masculino
Neuropeptídeos/farmacologia
Fragmentos de Peptídeos/farmacologia
Pregnanolona/biossíntese
Progesterona/biossíntese
Rana esculenta
Receptores de GABA-A/genética
Receptores de GABA-A/metabolismo
Técnicas de Cultura de Tecidos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Anti-Anxiety Agents); 0 (Complex Mixtures); 0 (GABA Modulators); 0 (GABA-A Receptor Antagonists); 0 (Isoquinolines); 0 (Neuropeptides); 0 (Oxazines); 0 (Peptide Fragments); 0 (Receptors, GABA-A); 120667-90-5 (triakontatetraneuropeptide); 145-14-2 (20-alpha-Dihydroprogesterone); 387-79-1 (17-alpha-Hydroxypregnenolone); 40P7XK9392 (Flumazenil); 459AG36T1B (Dehydroepiandrosterone); 4G7DS2Q64Y (Progesterone); BXO86P3XXW (Pregnanolone); X24X82MX4X (etifoxine); Y37615DVKC (Bicuculline); YNF83VN1RL (PK 11195)
[Em] Mês de entrada:1602
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150319
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0120473



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