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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Systematic relationships within the Litsea complex (Lauraceae)

Li, Jie. January 2001 (has links) (PDF)
Includes bibliographical references (leaves 242-252) A general description of the taxonomic history, embryology, palynology, karyology, anatomy and distribution of the Litsea complex and providing an improved classification for the complex and a key to the revised genera. System requirements for accompanying computer disk: IBM compatible computer. Other requirements: LucID Software.
2

Systematic relationships within the Litsea complex (Lauraceae) / by Jie Li.

Li, Jie January 2001 (has links)
Includes bibliographical references (leaves 242-252) / System requirements for accompanying computer disk: IBM compatible computer. Other requirements: LucID Software. / vi, 404 leaves, [85] leaves of plates : ill. ; 30 cm. + 1 computer disk; 3 1/2 in. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / A general description of the taxonomic history, embryology, palynology, karyology, anatomy and distribution of the Litsea complex and providing an improved classification for the complex and a key to the revised genera. / Thesis (Ph.D.(Sc.))--University of Adelaide, Dept. of Environmental Biology, 2001
3

Systematic relationships within the Litsea complex (Lauraceae) /

Li, Jie. January 2001 (has links) (PDF)
Thesis (Ph.D.(Sc.)) -- University of Adelaide, Dept. of Environmental Biology, 2001. / Includes bibliographical references (leaves 242-252).
4

Sistemática e filosofia: filogenia do complexo Ocotea e revisão do grupo Ocotea indecora (Lauraceae) / Systematics and philosophy: phylogeny of Ocotea complex and revision of Ocotea indecora group (Lauraceae)

Assis, Leandro Cézanne de Souza 21 May 2009 (has links)
Abordagens como homologia, construção de táxons e reconstrução da filogenia podem ser contextualizadas e investigadas por meio de uma conexão histórica e atual entre sistemática e filosofia. A presente tese defende essa conexão científico-filosófica, tendo como estudo de caso ambos o complexo Ocotea, que abrange 13 gêneros e 750 espécies predominantemente neotropicais, e o grupo Ocotea indecora, com 20 espécies e centro de diversidade na floresta atlântica do sudeste do Brasil. O capítulo 1 discute a conceitualização de táxons e homologias (táxica e transformativa) como ambos indivíduos e espécies naturais (ou agrupamentos de espécies com propriedade homeostática). Embora essas conceitualizações não sejam mutuamente exclusivas metafisicamente, a perspectiva das espécies naturais é defendida, enquanto a dos indivíduos desafiada, com base em uma motivação por aspectos empírico-pragmáticos e teórico-explicativos em sistemática e evolução. O capítulo 2 foca no renascimento da morfologia na sistemática filogenética, com base em duas teorias da verdade em epistemologia, i.e., coerência e correspondência, chamando para a unificação de ambas a teorias partir de uma teoria funderentista de justificação epistêmica das hipóteses de relação filogenética. O papel e o significado da morfologia também são discutidos no contexto de análises separadas e combinadas, paleontologia, espécies naturais, conceito de caráter, homologia, sinapomorfia, semaforonte, modularidade e taxonomia. O renascimento da morfologia não é apenas dependente de uma perspectiva científico-filosófica mas também depende de uma reforma política, econômica, social e educacional na sistemática contemporânea. O capítulo 3 é uma filogenia do complexo Ocotea com análise combinada de dados morfológicos e da região nuclear ribossômica ITS. São discutidos o papel e o significado das evidências morfológica e molecular, das análises separadas e combinadas, bem como modularidade e homologia. Subclados dentro do complexo Ocotea são inferidos e delimitados por sinapomorfias morfológicas. Uma perspectiva de classificação filogenética dos gêneros do complexo Ocotea também é fornecida. O capítulo 4 trata de mudanças taxonômicas e nomenclaturais no grupo O. indecora, basicamente sinonimizações, lectotopificações e uma nova combinação. O capítulo 5 é uma revisão do grupo O. indecora, com base na análise de ca. 550 coleções. Chave de identificação, descrições, bem como comentários sobre a circunscrição, distribuição, habitat, fenologia e relações taxonômicas das espécies do grupo são fornecidos. / Approaches as homology, construction of taxa, and phylogeny reconstruction can be contextualized and investigated through a historical and current connection between systematics and philosophy. The present thesis defends this scientific-philosophical connection, having as study case both the Ocotea complex, which embraces 13 genera and 750 species predominantly Neotropical, and the Ocotea indecora group, with 20 species and centre of diversity in the Atlantic forest from Southeastern Brazil. The chapter 1 discusses the conceptualization of taxa and homologies (taxic and transformative) as both individuals and natural kinds (or homeostatic property cluster kinds). Although these conceptualizations are not mutually exclusive metaphysically, the perspective of natural kinds is endorsed, whereas that of individuals challenged, based on the motivation for empirical-pragmatic and theoretical-explanatory aspects in systematics and evolution. The chapter 2 focuses on the renaissance of morphology in phylogenetic systematics based on two theories of truth in epistemology, i.e., coherence and correspondence, calling for a unification of both theories from a fundherentist theory of epistemic justification of hypotheses of phylogenetic relationship. The role and meaning of morphology are also discussed in the context of separate and combined analyses, paleontology, natural kinds, character concept, homology, synapomorphy, semaphoront, modularity, and taxonomy. The renaissance of morphology is not only dependent on a scientific-philosophical perspective but it is also dependent on a political, economic, social, and educational reform in contemporary systematics. The chapter 3 is a phylogeny of the Ocotea complex with combined analysis of morphology and ITS nuclear ribosomal region. The role and meaning of morphological and molecular evidence, separate and combined analyses, as well as modularity and homology are discussed. Subclades within the Ocotea complex are inferred and delimited by morphological synapomorphies. A perspective of phylogenetic classification of the genera of the Ocotea complex is provided. The chapter 4 treats of taxonomic and nomenclatural changes in the O. indecora group, basically synonyms, lectotypifications, and a new combination. The chapter 5 is a revision of O. indecora group based on the analysis of ca. 550 collections. Identification key, descriptions, as well as comments on its circumscription, distribution, habitat, phenology, and taxonomic relationships of its species are provided.
5

Sistemática e filosofia: filogenia do complexo Ocotea e revisão do grupo Ocotea indecora (Lauraceae) /

Assis, Leandro Cézanne de Souza. January 2009 (has links)
Thesis (doctoral)--Universidade de São Paulo, 2009. / Includes bibliographical references. Also available via the Internet: http://www.teses.usp.br/teses/disponiveis/41/41132/tde-15072009-151632/
6

Sistemática e filosofia: filogenia do complexo Ocotea e revisão do grupo Ocotea indecora (Lauraceae) / Systematics and philosophy: phylogeny of Ocotea complex and revision of Ocotea indecora group (Lauraceae)

Leandro Cézanne de Souza Assis 21 May 2009 (has links)
Abordagens como homologia, construção de táxons e reconstrução da filogenia podem ser contextualizadas e investigadas por meio de uma conexão histórica e atual entre sistemática e filosofia. A presente tese defende essa conexão científico-filosófica, tendo como estudo de caso ambos o complexo Ocotea, que abrange 13 gêneros e 750 espécies predominantemente neotropicais, e o grupo Ocotea indecora, com 20 espécies e centro de diversidade na floresta atlântica do sudeste do Brasil. O capítulo 1 discute a conceitualização de táxons e homologias (táxica e transformativa) como ambos indivíduos e espécies naturais (ou agrupamentos de espécies com propriedade homeostática). Embora essas conceitualizações não sejam mutuamente exclusivas metafisicamente, a perspectiva das espécies naturais é defendida, enquanto a dos indivíduos desafiada, com base em uma motivação por aspectos empírico-pragmáticos e teórico-explicativos em sistemática e evolução. O capítulo 2 foca no renascimento da morfologia na sistemática filogenética, com base em duas teorias da verdade em epistemologia, i.e., coerência e correspondência, chamando para a unificação de ambas a teorias partir de uma teoria funderentista de justificação epistêmica das hipóteses de relação filogenética. O papel e o significado da morfologia também são discutidos no contexto de análises separadas e combinadas, paleontologia, espécies naturais, conceito de caráter, homologia, sinapomorfia, semaforonte, modularidade e taxonomia. O renascimento da morfologia não é apenas dependente de uma perspectiva científico-filosófica mas também depende de uma reforma política, econômica, social e educacional na sistemática contemporânea. O capítulo 3 é uma filogenia do complexo Ocotea com análise combinada de dados morfológicos e da região nuclear ribossômica ITS. São discutidos o papel e o significado das evidências morfológica e molecular, das análises separadas e combinadas, bem como modularidade e homologia. Subclados dentro do complexo Ocotea são inferidos e delimitados por sinapomorfias morfológicas. Uma perspectiva de classificação filogenética dos gêneros do complexo Ocotea também é fornecida. O capítulo 4 trata de mudanças taxonômicas e nomenclaturais no grupo O. indecora, basicamente sinonimizações, lectotopificações e uma nova combinação. O capítulo 5 é uma revisão do grupo O. indecora, com base na análise de ca. 550 coleções. Chave de identificação, descrições, bem como comentários sobre a circunscrição, distribuição, habitat, fenologia e relações taxonômicas das espécies do grupo são fornecidos. / Approaches as homology, construction of taxa, and phylogeny reconstruction can be contextualized and investigated through a historical and current connection between systematics and philosophy. The present thesis defends this scientific-philosophical connection, having as study case both the Ocotea complex, which embraces 13 genera and 750 species predominantly Neotropical, and the Ocotea indecora group, with 20 species and centre of diversity in the Atlantic forest from Southeastern Brazil. The chapter 1 discusses the conceptualization of taxa and homologies (taxic and transformative) as both individuals and natural kinds (or homeostatic property cluster kinds). Although these conceptualizations are not mutually exclusive metaphysically, the perspective of natural kinds is endorsed, whereas that of individuals challenged, based on the motivation for empirical-pragmatic and theoretical-explanatory aspects in systematics and evolution. The chapter 2 focuses on the renaissance of morphology in phylogenetic systematics based on two theories of truth in epistemology, i.e., coherence and correspondence, calling for a unification of both theories from a fundherentist theory of epistemic justification of hypotheses of phylogenetic relationship. The role and meaning of morphology are also discussed in the context of separate and combined analyses, paleontology, natural kinds, character concept, homology, synapomorphy, semaphoront, modularity, and taxonomy. The renaissance of morphology is not only dependent on a scientific-philosophical perspective but it is also dependent on a political, economic, social, and educational reform in contemporary systematics. The chapter 3 is a phylogeny of the Ocotea complex with combined analysis of morphology and ITS nuclear ribosomal region. The role and meaning of morphological and molecular evidence, separate and combined analyses, as well as modularity and homology are discussed. Subclades within the Ocotea complex are inferred and delimited by morphological synapomorphies. A perspective of phylogenetic classification of the genera of the Ocotea complex is provided. The chapter 4 treats of taxonomic and nomenclatural changes in the O. indecora group, basically synonyms, lectotypifications, and a new combination. The chapter 5 is a revision of O. indecora group based on the analysis of ca. 550 collections. Identification key, descriptions, as well as comments on its circumscription, distribution, habitat, phenology, and taxonomic relationships of its species are provided.
7

Characterisation of biodiesel from Litsea glutinosa

Perumal, Alicia Ann 08 August 2014 (has links)
Submitted in complete fulfillment for the Degree of Master of Technology: Biotechnology, Durban University of Technology, Durban, South Africa, 2014. / Global warming is a major concern to the world’s population. It is caused by greenhouse gases that result from the burning of fossil fuel. The fossil fuel reserves are rapidly depleting as the needs and wants of man in the world increases. Biodiesel is one of the solutions proposed to remedy this environmental crisis facing the world today. The aim of this study was to characterise the biodiesel that can be produced from the oil of Litsea glutinosa by transesterification. Biodiesel can be used in a diesel engine without modification and be produced from many different natural renewable oil sources such as algae, plants and kitchen waste material. Jatropha curcas has been identified as a potential producer of oil for biodiesel. The biodiesel properties of Jatropha curcas meet the required American Society for Testing and Materials (ASTM) standards. The fruit of Jatropha curcas contains 40.0% lipids. The oil has a saponification number of 202.6 and an iodine value of 93.0. However Jatropha curcas cannot be grown in South Africa because it is a highly invasive plant. Cetane number is the most important parameter of biodiesel. The higher the cetane value, the better the quality of the biodiesel. Oil from Jatropha curcas has a cetane number of 57.1. An alternative is the oil from Litsea glutinosa, which is found as a naturalised free forest along the South African coastline, and is also found in many Asian countries. It has many medicinal properties, however, it is not edible and hence its use for biodiesel does not add to the debate of fuel versus food production. The cetane number of oil from Litsea glutinosa is 64.79, which is ideal for ignition, and the fruit with 61.29% lipids can yield valuable quantities of biodiesel. Thus, the aim of the research was to determine the potential of Litsea glutinosa as a source of biodiesel. Furthermore, to maintain a sustainable source, Litsea glutinosa was micropropagated, and transformation of Litsea glutinosa was attempted for hairy root cultures. The Clevenger apparatus was used to extract fatty acids from dried crushed fruit of Litsea glutinosa. Fatty acids were converted to fatty acid methyl esters by transesterification. Transesterification was conducted in the presence of nitrogen and the reaction was catalysed with a mixture of methanol and sodium hydroxide (NaOH). The ratio 1 : 3 of oil to catalyst mixture was used for optimum transesterification to ensure a forward reaction and it was transferred to a separating funnel to allow the glycerol and fatty acid methyl esters to separate. GC-MS was used to determine the fatty acids. The iodine number, saponification number, acid value, viscosity, kinematic viscosity, density, specific gravity, thermostability, distillation point and sulphur content were determined. The seeds of Litsea glutinosa were germinated and tissue culture callus was produced from the seeds and leaves. The leaves and stems were used to produce hairy root cultures by inoculating them with Agrobacterium rhizogenes. Litsea glutinosa yielded 61% oil, which included 47 fatty acids in the fruit and 24 fatty acids in the seeds. The fatty acid profile of the oils indicated that the predominant fatty acids present were those that are essential for good quality biodiesel. The dominant fatty acids found in the fruit were 65.4% 9-octadecenoic acid and 13.6% hexadecanoic acid. The dominating fatty acids found in the seeds contained 36.3% 9-octadecenoic acid, 13.9%, hexadecanoic acid and 39.1%, dodecanoic acid. The iodine value was 6.3. The saponification value was 274. The acid value was 0.45 mg KOH. g-1. The viscosity was 22.48 mm2. s-1 and the kinematic viscosity was 23.84 mm2. s-1. The density was 942.69 kg. m-3 and the specific gravity was found to be 0.9 g. cm-3. The distillation temperature ranged between 52.2°C to 610.2°C. The sulphur content was found to be 383 µg. ml-1. These characteristics indicate that Litsea glutinosa can be used as a source of biodiesel, because the properties meet the required ASTM standards. However, the production of biodiesel from Litsea glutinosa has not been commercialised because the production of fuel is dependent on the fruit of the plant, which is seasonal. To overcome this, a part of this study investigated micropragation of Litsea glutinosa and transformation of Litsea glutinosa by Agrobacterium rhizogenes into hairy roots and attempts where made to determine whether fatty acid could be produced by these techniques. Callus cultures were grown on MS media and McCowns woody plant media supplemented with 1 ml BAP and 1 ml 2,4-D per 1 L of media. Callus cultures were obtained in the light. However, Litsea glutinosa resisted transformation by Agrobacterium rhizogenes.
8

A systematic study on the genus Machilus of Taiwan (Lauraceae)

Lu, Sheng-you 28 August 2008 (has links)
Abstract The genus Machilus comprises about 100 species. They are distributing over the tropics and the subtropical zone, mainly in Easten Asia. Eight species and one variety are native plants of Taiwan, including M.konishiiHayata, M. kusanoi Hayata, M. mushaensis Lu, M. obovatifolia (Hayata) Kaneh. et. Sasaki, M. obovatifolia var. taiwuensis Lu & Chen, M. philippinensis Merr., M. pseudolongifolia Hayata., M. thunbergii Siebold & Zucc. and M. zuhoensis Hayata. Machilus japonica Siebold & Zucc. is regarded to be native in Japan, Ryukyu and Korea, but not native to Taiwan. Due to the morphological similarities among several taxa, species identification was a difficult task in the past. Although many scholars have worked on this topic, there are still many unresolved issues left, especially the relationships among M. japonica, M. pseudolongifolia, M. kusanoi, M. zuihonensis and M. mushaensis. This study aims to study Taiwan Machilus taxonomy with an emphasis on a detailed morphological study. In addition, essential oils, DNA sequences and isozymes were also studied. The results are list as follows: 1. Morphological taxonomy: Machilus japonica, M. pseudolongifolia., M. kusanoi, M. zuihonensis and M. mushaensis can be firmily classified into 5 taxa by morphologic characters. 2. Essential oils of leaves: The data of essential oils ca differentiate the closely related species, M. japonica, M. pseudolongifolia, M. kusanoi, M. zuihnensis and M. mushaensis from one another. The data also indicated that M. konishii is better placed in the genus Machilus than in the genus Nothophoebe. 3. DNA sequences: The sequences of the AG1 introns data clearly indicate that M. japonica is distinct from M. pseudolongifolia and M. kusanoi. 4. Isozymes: The data of isozyme analyses can distinctly distinguish the closely related species, M. japonica, M. pseudolongifolia and M. kusanoi. The data also can separate the closely related species, M. zuihonensis and M. mushaensis from each other. With the above data, the author believes that there is no naturally distributed M. japonica in Taiwan and the name M. pseudolongifolia should be used. Machilus pseudolongifolia, M. kusanoi, M. zuihoensis and M. mushaensis are all endemic to Taiwan and are morphologically diistinct. However, the DNA sequences of tested marker genes analyzed indicated that genetically they are not well differentiated. The differences among the DNA sequences of these species were not significant could be due to the possibly relatively short divergent time. Totally, eight indigenous species and one variety of the genus Machilus of Taiwan are recognized. For each species, a morphological description and classification treatment are provided; also included are geographical distribution, ecology, citation of exsiccatae, illustrations and images of type specimens etc.
9

Avaliação dos efeitos centrais da iangambina isolada de Ocotea duckei Vattimo: Estudo comportamental e neuroquímico em córtex motor e corpo estriado de camundongo / Evaluation of the central effects of yangambin isolated from Ocotea duckei Vattimo: Behavioral and neurochemical study in mice motor cortex and striatum

Lima, Vera Targino Moreira January 2005 (has links)
LIMA, Vera Targino Moreira. Avaliação dos efeitos centrais da iangambina isolada de Ocotea duckei Vattimo : estudo comportamental e neuroquímico em córtex motor e corpo estriado de camundongo. 2005. 189 f. Tese (Doutorado em Farmacologia) - Universidade Federal do Ceará. Faculdade de Medicina, Fortaleza, 2005. / Submitted by denise santos (denise.santos@ufc.br) on 2012-10-18T12:31:28Z No. of bitstreams: 1 2005_tese_vtmlima.pdf: 1807379 bytes, checksum: 8aba30578e507eb1cee9c1835d0be7ee (MD5) / Approved for entry into archive by Erika Fernandes(erikaleitefernandes@gmail.com) on 2012-10-22T12:11:10Z (GMT) No. of bitstreams: 1 2005_tese_vtmlima.pdf: 1807379 bytes, checksum: 8aba30578e507eb1cee9c1835d0be7ee (MD5) / Made available in DSpace on 2012-10-22T12:11:10Z (GMT). No. of bitstreams: 1 2005_tese_vtmlima.pdf: 1807379 bytes, checksum: 8aba30578e507eb1cee9c1835d0be7ee (MD5) Previous issue date: 2005 / The effects of the acute administration of yangambin (25, 50 and 75 mg/kg intraperitoneal and oral), were studied in some animals behavioral models (open field, rotarod, forced swimming test, barbiturate-induced sleeping time, hole board, elevated plus maze, pentilenotetrazole-induced convulsion). Binding in vitro with differents concentrations of yangambin (0.5-200 microlitre), had been carried out to evaluate its interaction with the dopaminergic receptors (D1- and D2-like), muscarinic receptors (M1+M2)-like and serotonergic receptors (5-HT2)-like, as well as, HPLC studies to determine the effects of yangambin (25, 50 e 75 mg/kg, i.p.) after 24 h of its acute administration on the monoamines levels and its metabolites in mice motor cortex and striatum. The results showed that yangambin induced a significant reduction in the locomotor activity and the frequencies of rearing and grooming in the open field test, indicative of possible ansiolytic-like effect. These results can have related with the dopaminergic system, since that it had interaction of the yangambin with D1- e D2-símile receptors, in striatum and D2-símile in motor cortex, followed by a dopamine reduction, indicating a probable dopaminergic antagonistic action. The yangambin did not cause alteration in the motor coordination of the animals in the rotarod test, suggesting that the reduction of the locomotor activity can involve central action. It had a significant increase in the immobility of the mice in the forced swimming test induced by the yangambin. This effect, taken together with the reduction of the dopamine, noradrenaline and serotonin induced by yangambin in striatum, can explain its depressant effect in this model. Moreover, corroborating these results, the yangambin increased pentobarbital-induced sleeping time in treated mice, suggestive of central depressant effect. Yangambin in the doses used in this work, did not protect the animals from pentilenotetrazole-induced convulsions, suggesting that this effect depends on the used dose. In the hole board test, the yangambin increased the number of the head dips, in all the doses studied, intraperitoneal or oral, demonstrating ansiolytic activity. The ansiolytic effect of yangambin (75 mg/kg, i.p. and 25, 50 and 75 mg/kg, p.o.) was also confirmed in the elevated plus maze, where it presented significant increase in the percentage of the entries number in the open arms and the percentage of the time of permanence in the open arms. Yangambin 50 and 75 mg/kg, p.o., also increased the number of entries and the time of permanence in the open arms, respectively. However, yangambin 25 and 50 mg/kg, i.p., presented ansiogenic effect evidenced by the reduction of the time of permanence in the open arms which probably due to the absence of the formation of some active metabolite generated in the first-pass metabolism. The ansiolytic effect induced for yangambin 75 mg/kg, p.o., in the plus maze, was reverted with flumazenil (2.5 mg/kg, i.p.), indicating the possible participation of the GABAergic receptors in its mechanism of action. The ansiolytic effect of the yangambin, observed in the hole board and the plus maze test, was followed by a reduction of noradrenaline and serotonin in striatum, however, in the motor cortex, yangambin (75 mg/kg, i.p.), induced an increase of the noradrenaline levels, as well as yangambin (25, 50 and 75 mg/kg, i.p.) induced serotonin increase, demonstrating that the ansiolytic effect associated to the reduction of noradrenaline and serotonin depends on the cerebral area. The blockade of the dopaminergic receptors induced by yangambin was synergic to its agonist action on the cholinergic receptors, since that it did not modify the reduction of the locomotive activity of the animals in the open field test. The present work shows an interaction between the systems dopaminergic, cholinergic, serotonergic and GABAergic, that suggest the importance of yangambin in illnesses that modify these systems of neurotransmission. The yangambin presented compatible behavioural and neurochemical alterations with ansiolytic-like effect. / Os efeitos da administração aguda da iangambina (25, 50 e 75 mg/kg, por via intraperitoneal e oral), foram estudados em vários modelos animais de comportamento (campo aberto, rota rod, nado forçado, tempo de sono induzido por pentobarbital, placa perfurada, labirinto em cruz elevado, convulsão induzida por pentilenotetrazol). Binding in vitro com diferentes concentrações de iangambina (0,5-200 microlitros), foram realizados para avaliar sua interação com os receptores dopaminérgicos (D1- e D2-símile), receptores muscarínicos (M1+M2)-símile e receptores serotonérgicos (5-HT2)-símile, bem como, estudo em HPLC para determinar os efeitos da iangambina (25, 50 e 75 mg/kg,i.p.) após 24 horas de sua administração aguda sobre os níveis de monoaminas e seus metabólitos em córtex motor e corpo estriado de camundongos. Os resultados mostraram que a iangambina induziu uma diminuição significativa na atividade locomotora e nas freqüências de rearing e grooming no teste de campo aberto, indicativo de possível efeito ansiolítico. Estes resultados podem estar relacionados com o sistema dopaminérgico, desde que houve interação da iangambina com os receptores D1- e D2-símile, em corpo estriado e D2-símile em córtex motor, acompanhado de uma redução de dopamina, indicando uma provável ação antagonista dopaminérgica. A iangambina não causou alteração na coordenação motora dos animais no teste de rota rod, sugerindo que a redução da atividade locomotora possa envolver ação central. Houve um aumento significativo na imobilidade dos camundongos no teste do nado forçado induzido pela iangambina. Este efeito, juntamente com a redução da dopamina, noradrenalina e serotonina induzida pela iangambina em corpo estriado, pode explicar seu efeito depressor neste modelo. Além disso, corroborando estes resultados, a iangambina potenciou o tempo de sono induzido pelo pentobarbital em camundongos, sugestivo de efeito depressor central. Iangambina nas doses empregadas neste trabalho, não protegeu os animais das convulsões induzidas por pentilenotetrazol, sugerindo que este efeito depende da dose usada. No teste da placa perfurada, a iangambina aumentou o número de head dips, em todas as doses estudadas, por via intraperitoneal ou oral, demonstrando atividade ansiolítica. O efeito ansiolítco da iangambina (75 mg/kg, i.p e 25, 50 e 75 mg/kg, v.o.) também foi confirmado no teste do labirinto em cruz elevado, onde apresentou aumento significativo na percentagem do número de entradas nos braços abertos e na percentagem do tempo de permanência nos braços abertos. Iangambina (50 e 75 mg/kg, v.o.) também aumentou o número de entradas e o tempo de permanência nos braços abertos, respectivamente. No entanto, iangambina 25 e 50 mg/kg, i.p., apresentou efeito ansiogênico evidenciado pela redução do tempo de permanência nos braços abertos o que provavelmente pode dever-se a ausência da formação de algum metabólito ativo gerado no metabolismo de primeira passagem. O efeito ansiolítico induzido pela iangambina 75 mg/kg, v.o., no modelo do labirinto, foi revertido com o flumazenil (2,5 mg/kg,i.p), indicando a possível participação dos receptores GABAérgicos no seu mecanismo de ação. O efeito ansiolítico da iangambina, observado no teste da placa perfurada e no labirinto em cruz elevado, foi acompanhado por uma redução de noradrenalina e serotonina em corpo estriado, no entanto, em córtex motor, iangambina (75 mg/kg, i.p.), induziu um aumento dos níveis de noradrenalina, assim como iangambina (25, 50 e 75 mg/kg, i.p.) induziu aumento de serotonina, demonstrando que o efeito ansiolitico associado a redução de noradrenalina e serotonina depende da área cerebral. A iangambina interagiu com receptores muscarínicos em córtex motor e corpo estriado. O bloqueio dos receptores dopaminérgicos induzido pela iangambina foi sinérgico à sua ação agonista sobre os receptores colinérgicos, desde que não alterou a redução da atividade locomotora dos animais no modelo de campo aberto. O presente trabalho mostra uma interação entre os sistemas dopaminérgico, colinérgico, serotonérgico e GABAérgico, revelando a importância da iangambina em doenças que alteram estes sistemas de neurotransmissão. A iangambina apresentou alterações comportamentais e neuroquímicas compatíveis com efeito ansiolítico-símile.
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Vasodilatação causada pelo 1-nitro-2-feniletano em aorta de rato : provável estimulação da guanilato ciclase / Vasodilation caused by the 1-nitro-2-phenylethane in rat aorta : probable stimulation of guanylate cyclase

Brito, Teresinha Silva de January 2012 (has links)
BRITO, Teresinha Silva de. Vasodilatação causada pelo 1-nitro-2-feniletano em aorta de rato : provável estimulação da guanilato ciclase. 2012. 105 f. Dissertação (Mestrado em Farmacologia) - Universidade Federal do Ceará. Faculdade de Medicina, Fortaleza, 2012. / Submitted by denise santos (denise.santos@ufc.br) on 2013-07-26T11:48:12Z No. of bitstreams: 1 2012_dis_tsbrito.pdf: 5911819 bytes, checksum: aa0eba5915de704484ec5f3bc2d5bbc7 (MD5) / Approved for entry into archive by Erika Fernandes(erikaleitefernandes@gmail.com) on 2013-08-06T11:52:06Z (GMT) No. of bitstreams: 1 2012_dis_tsbrito.pdf: 5911819 bytes, checksum: aa0eba5915de704484ec5f3bc2d5bbc7 (MD5) / Made available in DSpace on 2013-08-06T11:52:07Z (GMT). No. of bitstreams: 1 2012_dis_tsbrito.pdf: 5911819 bytes, checksum: aa0eba5915de704484ec5f3bc2d5bbc7 (MD5) Previous issue date: 2012 / It was early shown that intravenous treatment with 1-nitro-2-phenylethane (NPE) induced hypotension resulting mainly from its direct vasodilatory action on vascular smooth muscle. Here, it was sudied the underlying mechanism involved in the vasorelaxant effect of NPE in isolated rings of rat arteries. Isometric recordings were obtained from rings made from aorta or mesenteric artery using a digital acquisition system. Experiments in silico (docking) for simulation of molecular interactions between NPE and the enzyme guanylate cyclase were performed. In endothelium-intact aortic preparations, NPE (1-300 g/mL) relaxed the phenylephrine or K+-induced contractions with IC50 values of 35.0 [23.3- 52.6] and 73.2 [39.5-134.3] g/mL, respectively. Vasorelaxant effects of NPE were significantly (P <0.05, Mann-Whitney test) decreased by pretreatment with ODQ (10 µM), methylene blue (10 µM), TEA (5 mM), glibenclamide (10 µM) or 4-aminopyridine (1 mM) but not by vascular endothelium removal or by pretreatment with L-NAME (100 µM), indomethacin (10 µM), MDL-12.330A (3 µM), KT5823 (0.5 µM ) or KT5720 (1 µM). Pharmacological potency of NPE was significantly greater (p <0.01, Mann-Whitney test) in preparations of mesenteric artery compared to that of aorta, as in K+- and norepinephrine-induced contraction with IC50 values of 5.3 [2.6-10.5] and 6.5 [2.8-14.9] g/mL, respectively. In calcium-free medium, in presence of K+ 60 mM or phenylephrine 1 μM, the CaCl2-induced contractions were significantly reduced and almost abolished by NPE at 100 μg/mL, respectively. In calcium-free medium, containing EGTA, the contractile response of phenylephrine was significantly reduced by NPE (100 g/mL), an effect prevented by treatment with ODQ (10 µM), whereas NPE was deprived of any significant effect on caffeine-induced contractions. Similar results were obtained with sodium nitroprusside. NPE also inhibited the contractions induced by the capacitive calcium entry or by phorbol ester. In addition, docking results revealed clusters of interactions of NPE with the guanylate cyclase molecule. The present study suggests that vasorelaxant activity of NPE on rat aorta is due to its stimulatory properties on guanylate cyclase, which activates the guanylate cyclase/cGMP/K+ channels pathway. / Previamente, foi demonstrado que o tratamento via intravenosa com 1-nitro-2-feniletano (NFE) induziu hipotensão que resulta principalmente de sua ação vasodilatadora diretamente sobre o músculo liso. Nesse estudo, estudamos o mecanismo subjacente ao efeito miorrelaxante do NFE em tecidos vasculares isolados de ratos. Registros isométricos foram obtidos a partir de anéis isolados de artéria aorta e do segundo ramo da mesentérica de ratos através de sistema de aquisição de dados. Experimentos in silico (docking) de simulação da formação de complexos entre o NFE e a enzima guanilato ciclase foram realizados. Em preparações de aorta isolada com endotélio intacto, NFE (1-300 g/mL) relaxou a contração induzida por fenilefrina ou K+, com valores de CI50 de 35,0 [23,3–52,6] e 73,2 [39,5–134,3] g/mL, respectivamente. Os efeitos vasorrelaxantes do NFE foram significativamente (P < 0,05, teste de Mann-Whitney) reduzidos pelo tratamento prévio com ODQ (10 µM), azul de metileno (10 µM), TEA (5 mM), glibenclamida (10 µM) ou 4-aminopiridina (1 mM), mas não pela remoção do endotélio vascular ou pelo pré-tratamento com L-NAME (100 μM), indometacina (10 μM), MDL-12.330A (3 μM), KT5823 (0.5 µM) ou KT5720 (1 μM). A potência do NFE para induzir efeito vasorrelaxante foi significantemente maior (p < 0,01, teste de Mann-Whitney) nas preparações de artéria mesentérica quando comparado à aorta, tanto nas contrações induzidas por K+ como por noradrenalina com valores de CI50 de 5,3 [2,6–10,5] e 6,5 [2,8–14,9] µg/mL, respectivamente. Em um meio sem cálcio, na presença de K+ 60 mM ou fenilefrina 1 µM, as contrações induzidas CaCl2 foram significativamente reduzidas e até mesmo abolidas pelo NFE na concentração de 100 µg/mL, respectivamente. Em meio sem cálcio, contendo EGTA, a resposta contrátil da fenilefrina foi significantemente reduzida pelo NFE (100 µg/mL ), efeito impedido pelo tratamento com ODQ (10 µM), enquanto não teve efeito significativo sobre as contrações induzidas por cafeína. Resultados semelhantes foram obtidos com nitroprussiato de sódio. NFE também foi capaz de inibir a contração induzida pela entrada capacitativa de cálcio e pelo éster de forbol. Além disso, os resultados de docking revelam que existem clusters de prováveis interações do NFE com a enzima guanilato ciclase. O presente estudo sugere que a atividade vasorrelaxante do NFE em aorta de rato é causada por provável estimulação da guanilato ciclase e consequente ativação da cascata enzimática guanilato ciclase/GMPc/canais de K+.

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