Dissertations / Theses on the topic 'Prostaglandins Antagonists'

The fever response, besides being part of host defense response to infection or inflammation, is associated with discomfort and anxiety and may constitute a risk for febrile seizures in children. Therefore, antipyretic therapy is routinely prescribed for febrile patients. The animal models of fever using the systemic injection of lipopolysaccharide (LPS) and Baker yeast, described in the literature, are suitable for screening of novel antipyretics, but they do not provide information regarding the mechanism of action of these compounds. Therefore, the present study aimed to describe and validate a model of fever induction by prostaglandin (PG) E2, the final mediator of febrile response in the central nervous system, in young male Wistar rats (25-30 days of age). In this protocol, PGE2 was injected intrathecally without implantation of cannula. Rectal temperature (TR) was recorded every thirty minutes for three hours after PGE2 injection (08:00 11:00 h). The intrathecal (i.t.) injection of PGE2 10 ηg in 100 μL/animal induced fever in the animals, which was prevented by administration of EP1 and EP3 receptors antagonists, but did not by antagonist of EP4 receptor. In addition, the classic antipyretics dipyrone and acetaminophen, at doses that had no effect per se on TR of animals, did not revert the fever induced by i.t. injection of PGE2. This model seems suitable to investigate whether the action of antipyretics occurs upstream or downstream the prostaglandin coupling in EP receptors. In addition, this protocol is advantageous from the technical, ethical and economical point of view compared to others PGE2-induced fever protocols described in the literature, because trepanation for cannula implantation is not required, reducing the inflammatory response, animals suffering and experimental costs.
A febre, apesar de fazer parte da resposta de defesa do hospedeiro à infecção ou inflamação, está associada com desconforto e ansiedade, além de representar um risco iminente de convulsões febris em crianças. Por isso, terapia antipirética é rotineiramente prescrita a pacientes febris. Os modelos animais de febre empregando a injeção sistêmica de lipopolissacarídeo (LPS) e fermento de padeiro, descritos na literatura, são úteis para a triagem de novos antipiréticos, mas não fornecem informações a respeito do mecanismo de ação desses compostos. Diante disso, o presente estudo objetivou padronizar e validar um modelo de indução de febre por prostaglandina (PG) E2, o mediador final da resposta febril no sistema nervoso central, em ratos machos jovens da raça Wistar (25-30 dias). Neste protocolo, a PGE2 foi injetada pela via intratecal (i.t.), não necessitando a implantação de cânula. A temperatura retal (TR) foi registrada a cada trinta minutos durante três horas após a injeção da PGE2 (08:00-11:00 h). A injeção i.t. de PGE2 10 ηg em 100 μL/animal induziu febre nos animais, a qual foi prevenida pela administração de antagonistas dos receptores EP1 e EP3, mas não por antagonista do receptor EP4. Além disso, os antipiréticos clássicos dipirona e paracetamol, em doses que não tiveram efeito per se na TR dos animais, não reverteram a febre induzida por PGE2 i.t. Este modelo parece útil para investigar se a ação dos antipiréticos ocorre antes ou depois da ligação da PGE2 em seus receptores EP. Além disso, este protocolo é vantajoso do ponto de vista técnico, ético e econômico em relação aos outros protocolos de indução de febre por PGE2 descritos na literatura, porque a trepanação para implantação de cânula não é necessária, reduzindo a resposta inflamatória, o sofrimento dos animais e os custos experimentais.

Le thromboxane a#2 est un puissant constricteur des muscles lisses vasculaires et respiratoires ainsi qu'un agent de l'agregation plaquettaire. Il est implique dans des pathologies respiratoires, cardiovasculaires et renales. Compte tenu de l'etude des caracteristiques communes a de nombreux antagonistes connus, notre but etait de preparer des antagonistes des recepteurs du thromboxane a#2 possedant une structure 2-azanorbornane et ayant une fonction sulfone sur l'atome d'azote, ainsi que la chaine superieure, plus ou moins modifiee, des prostaglandines. Les differentes molecules obtenues ont ensuite ete soumises a des tests pharmacologiques in vivo sur les recepteurs vasculaires chez le rat conscient et in vitro sur les recepteurs plaquettaires chez le cobaye ; alors que les tests in vitro se sont averes en majorite negatifs, les tests in vivo ont permis de mettre en evidence une activite antagoniste sur les recepteurs vasculaires

Prostaglandin E2 (PGE2), a metabolite of arachidonic acid, plays a role in water and sodium reabsorption in the collecting duct of the kidney. The collecting duct is responsible for the fine tuning of water and electrolytes. Only a small fraction of the filtered water and sodium is reabsorbed in the collecting duct, a fraction crucial to the regulation of water and electrolyte balance. This current study addresses the role of EP1, one of four PGE2 receptors, in the collecting duct. It is well documented that PGE2 inhibits sodium and water reabsorption in the collecting duct, however the exact mechanism is still debated. To determine whether the EP1 receptor mitigates AngII renal effects, an in vivo study was performed with EP1-/- mice. Global EP1-/- knockout mice were crossed with a renin overexpressing mouse line (herein denoted as “Ren”) and subjected to a high salt (HS) and low salt (LS) diet. Ren mice displayed an 11mmHg increase in systolic blood pressure (BP) on a HS diet and a decrease in BP of 14mmHg on a LS diet compared to the normal salt (NS) diet. Ren EP1-/- mice did not display a significant increase or decrease in BP on a HS or LS diet. On a LS diet, Ren EP1-/- displayed a drop in urine osmolarity (1641 mOsm/ kgH2O) vs. wild type (WT) mice (2107 mOsm/ kgH2O), consistent with increased sodium reabsorption. Narrowing in on the collecting duct, Ren EP1-/- mice had enhanced αENaC levels compared to Ren mice. In ex vivo microperfusion experiments, EP1-/- tubules show no response to PGE2 in the presence of AVP, whereas PGE2 inhibits AVP induced water reabsorption in WT mice. An increase in αENaC membrane accumulation due to EP1 gene ablation results in increased sodium reabsorption subsequently leading to a rise in BP. This contributes to the lack of salt sensitivity in EP1-/- mice. Overall, the EP1 receptor in the collecting duct represents a potential therapeutic target for the treatment of hypertension.

Le thromboxane a2 est un puissant agent constricteur des muscles lisses et un agregant des plaquettes sanguines. Il intervient dans des pathologies cardiovasculaires et respiratoires. Au vu de la litterature, notre but etait d'obtenir des antagonistes des recepteurs du thromboxane a2 ayant un squelette 2-azanorbornane et incluant une fonction sulfonee sur l'azote, ainsi que la chaine alpha des prostaglandines (6 ou 7 atomes de carbone). La molecule finale comportant la chaine 5-hexenoique, a ete testee sur les recepteurs vasculaires chez le rat conscient normo-tendu, par observation des reponses du u 46619, agoniste connu des memes recepteurs: il s'est avere presenter une activite partielle et fugace a la dose de 50 mg/kg

Le thromboxane a#2 est un puissant agent constructeur des muscles lisses et un agregant plaquettaire implique dans l'hypertension arterielle, l'infarctus du myocarde, l'asthme et des maladies renales. Nous basant sur des caracteristiques communes a un grand nombre d'antagonistes connus, nous avons synthetise des molecules presentant comme structure de base un squelette 7-azanorbornane et la chaine superieure, complete ou non, des prostaglandines. Le squelette est obtenu par une reaction de diels-alder thermique entre le pyrrole 1-carboxylate de tertiobutyle et l'acetylene dicarboxylate de methyle. Le cycloadduit obtenu a pu etre transforme en aldehyde-ester sature selon deux voies. La premiere, apres l'hydrure de lithium et d'aluminium ; cependant, l'aldehyde est obtenu en melange d'isomeres. La seconde voie donne, par saponification, hydrogenation puis reduction selective de l'acide, un isomere pur. Cet aldehyde nous a alors permis, par reaction de wittig, d'introduire la chaine superieure de prostaglandines a six atomes de carbone. La chaine complete a pu etre obtenue par homologation de l'aldehyde puis condensation de wittig. Apres modification du substituant de l'azote, les molecules obtenues ont ete biologiquement testees soit in vitro sur des plaquettes de cobaye, soit in vivo sur des rats conscients. D'autres etudes ont ete menees en parallele pour eliminer la fonction ester restante sur le cycle de base et pour introduire une seconde fonction azotee dans la molecule. Ces dernieres voies n'ont pu encore aboutir

Os AINEs constituem uma importante classe de fármacos com aplicações terapêuticas que já têm sido utilizadas por mais de um século. A evolução do tratamento de doenças inflamatórias crônicas, tais como artrite reumatóide e a osteoartrite tem seu marco a partir da indometacina, um dos representantes dos AINEs tradicionais, para posterior ascensão e mais recentemente o desuso de inibidores com grande seletividade para PGHS-2. O esforço para a descoberta de um fármaco mais seguro e eficaz continua a ser um desafio e a busca por novos agentes antiinflamatórios e analgésicos tem levado ao planejamento e a obtenção de inúmeras acil e arilidrazonas ativas de diversos padrões estruturais. Existem vários ligantes ativos capazes de atuar sobre a cascata do ácido araquidônico cujos resultados identificaram as subunidades acil e arilidrazônicos como grupo farmacofórico importante para inibição do processo inflamatório. Apesar da racionalização dos resultados obtidos e de estudos da relação estrutura-atividade no perfil biológico das subunidades acil e arilidrazonas, não foi possível até o momento identificar de fato o mecanismo de ação de tais grupamentos. O safrol, que é um alilbenzeno de distribuição ampla no reino vegetal, possui propriedades físico-químicas interessantes para ser utilizado como um produto de partida para a síntese das novas moléculas planejadas, sendo amplamente empregado em projetos de pesquisas no Laboratório de Fitoquímica e Química Medicinal (LFQM) na Universidade Federal de Alfenas (Unifal- MG). Este trabalho descreve o planejamento e síntese de novos derivados indanohidrazônicos candidatos a protótipos de fármacos anti-inflamatórios. A rota sintética foi planejada em três etapas, utilizando reagentes de baixo custo e metodologias relativamente simples. Os compostos planejados e obtidos foram avaliados com o intuito de se observar o efeito anti-inflamatório a partir de ensaios preliminares (número de contorções abdominais induzidas por ácido acético) realizadas no Instituto Biomédico da Universidade Federal Fluminense – UFF. Foi possível identificar que todos os congêneres apresentaram inibição sendo que os mais ativos da série das moléculas sintetizadas foram os derivados (1c) e (1e) com 51,0% e 48,6% de inibição das contorções abdominais induzidas por ácido acético, respectivamente.
NSAIDs are an important class of drugs with therapeutic applications that have already been used by more than a century. The evolution of treatment of chronic inflammatory diseases such as rheumatoid arthritis and osteoarthritis has its mark from indomethacin, one of the representatives of traditional NSAIDS for later rise and more recently the disuse of inhibitors with high selectivity for PGHS-2. The effort to discover safer and more effective drug remains a challenge and the search for new anti-inflammatory agents and analgesics have led to the planning and the discovery of numerous active acyl and aryl-hydrazones. And there are several active ligands able to act on the arachidonic acid cascade results identified subunits acyl and aryl-hydrazones as important pharmacophore for inhibition of the inflammatory process. Despite the rationalization of the results and studies of structure-activity relationship in the biological profile of the subunits acyl and aryl-hydrazones, we could not yet identify because of the mechanism of action of such groups. Safrole, which is a allylbenzene wide distribution in the plant kingdom, has interesting physical and chemical properties for use as a starting product for the synthesis of new molecules designed and is widely used in research projects at the Laboratory of Phytochemistry and Medicinal Chemistry . This paper describes the design and synthesis of new indane-hydrazone candidates prototype antiinflammatory drugs. The synthetic route was planned in three stages, using reagents of low cost and relatively simple methods. The compounds obtained were planned and evaluated in order to observe the anti-inflammatory effect from preliminary tests (number of writhing induced by acetic acid) held in the Biomedical Institute of Universidade Federal Fluminense - UFF. It was possible to identify all congeners showed that inhibition was the most active of the series of synthesized molecules was derived (1c) and (1e) with 51.0% and 48.6% inhibition of writhing induced by acetic acid.
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES

The F prostanoid receptor (FP receptor) is a GPCR that, upon binding of prostaglandin F2alpha (PGF2alpha), mediates IP3 production and PKC-dependent MAPK activation. We report that AL-8810, a characterized antagonist for PGF2alpha-dependent IP3 production, potently activates ERK1/2 in a PKC-independent manner, since PGF2alpha induced PKCbeta1-GFP translocation, while AL-8810 did not. AL-8810, though, induced EGFR phosphorylation, and the resultant ERK1/2 activation was inhibited by an EGFR antagonist, which suggested a transactivation signalling pathway. Batimastat, a matrix metalloprotease (MMP) inhibitor abolished both AL-8810- and PGF2alpha-induced ERK1/2, and therefore PGF2alpha may also signal through EGFR-independent transactivation. In osteoblasts, both PGF2alpha and AL-8810 activated MAPK in an EGFR-dependent manner, though PKC remained essential for PGF2alpha, as IL-6 and cell proliferation (known PKC effects) were induced by PGF2alpha but not AL-8810. Here, we highlight the biased signalling of AL-8810 on FP receptor produced MAPK through EGFR-MMP-mediated transactivation and also suggest a novel PGF2alpha-induced PKC-MMP, EGFR-independent, pathway.
Le récepteur F-prostanoïde (FP) est un récepteur de la famille des RCPG (récepteurs couplés aux protéines G), qui, une fois lié par son ligand naturel, la prostaglandine F2alpha (PGF2alpha), induit la production d'IP3, menant à l'activation de la protéine kinase C (PKC) suivie de l'activation des MAP kinases ERK1/2. Dans ce manuscrit, nous démontrons que l'AL-8810, étant reconnu comme un antagoniste de la production d'IP3 induite par le PGF2alpha, est capable d'activer la voie des ERK1/2 d'une manière indépendante à la PKC. En effet, nous démontrons que la PKCbeta1-GFP transloque à la membrane plasmique suite au traitement avec la PGF2alpha, alors que l'AL-8810 n'induit aucune translocation. Cependant, l'AL-8810, contrairement à la PGF2alpha, est capable d'induire la phosphorylation du récepteur à l'EGF (EGFR), menant à l'activation de ERK1/2. La phosphorylation de l'EGFR induite par l'AL-8810 est blocable par une antagoniste de l'EGFR, suggérant un mécanisme de transactivation de ce dernier. De plus, le batimastat, un inhibiteur non-spécifique des métalloprotéases matricielles (MMP) abolit l'induction des ERK1/2 par la PGF2alpha ainsi que par l'AL-8810, suggérant que la PGF2alpha signale probablement par un mécanisme indépendant de la transactivation de l'EGFR. Dans des cellules ostéoblastes, la PGF2alpha et l'AL-8810 activent ERK1/2 d'une manière dépendante au EGFR, même si la PKC demeure essentielle pour l'activation des voies en aval de la PGF2alpha, puisque l'interleukine-6 et la prolifération cellulaire (tous deux dépendants de la PKC) sont induits seulement par la PGF2alpha. En conclusion, nous montrons l'activation biaisée du FP par l'AL-8810 menant à l'activation de ERK1/2 via un mécanisme de transactivation par la voie EGFR-MMP. Ces résultats suggèrent aussi un nouveau mécanisme d'activation de ERK1/2 indépendant du EGFR et induit par la voie PKC-MMP.

Introduction: Cough is the commonest reason for which medical advice is sought. In assessment of chronic cough and in developing anti-tussive medications, inhalational cough challenges with capsaicin and citric acid are commonly employed. However the ability of these inhalational cough challenges to distinguish health and disease is not clear and it is not known which end point is best in making such assessments. Methods: Subjects belonging to five different categories (healthy volunteers, subjects with COPD, asthma, healthy current smokers and chronic cough) were compared with each another by using the standard cough challenges employing Capsaicin and Citric acid and also by using newer inhalational cough challenge agents such as prostaglandin E2 and bradykinin. In addition adaptation to repeated inhalations of tussive agents was also assessed. The relationship between the cough reflex sensitivity as gauged by using inhalational cough challenge tests and objective cough recording was explored in all five groups. Finally the change in C5 in Capsaicin evoked cough by using a substance to block TRPV1 channel and its effect on objective cough recording was assessed in subjects with chronic cough. Results: Different tussive agents have different abilities to distinguish between different diagnostic categories and a combination of inhalational cough challenge tests have a better accuracy of predicting diagnostic groups as compared to one on its own. There are significant differences in the rates of adaptation to repeated inhalations of PGE2 and there is a significant reduction in cough response over period of time in all disease groups. Using the TRPV1 antagonist resulted in a modest increase in the Log C5 concentration of capsaicin but this was not matched by a change in objective cough recording or CQLQ scores. Conclusions: The different abilities of tussive agents to distinguish between different diagnostic categories suggest that the information conveyed by the one inhalational cough challenge test is different from that by another test. The choice of the inhalational cough challenge test should therefore depend on which groups are included in the study. There was no significant difference in the rate of adaptation to prolonged challenge with citric acid or capsaicin and no significant correlation of the magnitude of adaptation with objective cough recording suggesting that this is unlikely to be responsible for the increased cough rates seen in diseases such as chronic cough, COPD or asthma. The TRPV1 antagonist did not result in a significant change in objective cough recording or CQLQ scores. The change in C5 with the TRPV1 antagonist was however modest and this may be reason for this study failing to show a relationship between these different measures.

Les ligands orthostériques transmettent un signal complexe aux cellules en se fixant à l'intérieur de la pochette de liaison de leur récepteur cible. Le changement conformationel qui en résulte modifie l'efficacité du récepteur à recruter et activer les seconds messagers en amont des voies de signalisation, soit les protéines G hétérotrimériques dans le cas des récepteurs couplés aux protéines G (GPCRs). Ces variations entraînent une vaste gamme de modifications dans le milieu intracellulaire. Par exemple, l'activation de la protéine G q provoque entre autres l'activation de la phospholipase C? (PLC? ), la production d'inositol 1,4,5-trisphosphate (1P3), puis l'activation des protéines kinases C (PKC). L'activation de la protéine G s , pour sa part, stimule l'activité de l'adénylate cyclase (AC), ce qui entraîne la production d'AMPc et l'activation de la protéine kinase A (PKA). Un ligand n'influence pas nécessairement deux voies de signalisation indépendantes de façon similaire, ce qui lui confère la propriété de sélectivité fonctionnelle. Dans ce travail, nous avons caractérisé le profil pharmacologique de ligands orthostériques du récepteur FP de la PGF2? à l'aide d'un clone HEK-293-SL exprimant le récepteur FP de façon stable. La mesure de la production d'IP3 a permis d'évaluer la voie de la PLC alors que la mesure de la production d'AMP c a permis d'évaluer la voie de l'AC. Pour chacune d'entre elles, le fluprostenol s'est comporté comme un agoniste complet moins puissant que l'agoniste naturel. Le composé synthétique Al-8810 s'est comporté comme un agoniste partiel de la voie de la PLC, alors qu'il s'est avéré être un antagoniste de la voie de l'AC. Ces résultats démontrent que l'activité d'un ligand vis-à-vis un récepteur dépend du groupe d'effecteurs observé, ce qui illustre le concept de sélectivité fonctionnelle des ligands. L'étude des composés allostériques THG113 et THG113.824 démontre que ces derniers n'influencent pas la signalisation déclenchée en aval du récepteur FP par son agoniste naturel. Ces résultats suggèrent qu'ils agiraient comme antagoniste des effets de la PGF 2? par un mécanisme indépendant du récepteur FP. [Symboles non conformes]

Submitted by Anderson Silva (avargas@icict.fiocruz.br) on 2012-11-30T11:59:08Z No. of bitstreams: 1 fabio_p_m_santos_ioc_bcm_0037_2011.pdf: 10305796 bytes, checksum: 74de5b830c8354cd532f74bd40993c6a (MD5)
Made available in DSpace on 2012-11-30T11:59:08Z (GMT). No. of bitstreams: 1 fabio_p_m_santos_ioc_bcm_0037_2011.pdf: 10305796 bytes, checksum: 74de5b830c8354cd532f74bd40993c6a (MD5) Previous issue date: 2011
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.
Durante a resposta alérgica, dentre os vários mediadores inflamatórios de natureza lipídica, a prostaglandina D2 (PGD2) é considerada um mediador-chave. Em adição aos seus conhecidos efeitos quimiotáticos para eosinófilos, recentemente, foi descrito que a PGD2 é também capaz de promover a ativação dos eosinófilos, induzindo a biogênese de corpúsculos lipídicos e a síntese de leucotrieno C4 (LTC4) nessas organelas recém-formadas. Esses efeitos são atribuídos a ação da PGD2 sobre seus 2 receptores – DP1 e DP2 – os quais encontram-se expressos de maneira constitutiva na membrana dos eosinófilos. Então, o objetivo principal do estudo foi identificar o receptor específico da PGD2 envolvido no mecanismo de síntese de LTC4 por eosinófilos estimulados com PGD2. In vivo, num modelo murino de pleurisia alérgica e induzida por PGD2, a utilização dos antagonistas seletivos do receptor DP1 (BW A868c) ou do receptor DP2 (CAY10471) inibiu a síntese de LTC4 nessas respostas inflamatórias. No entanto, somente BWA868C foi capaz de inibir a biogênese de corpúsculos lipídicos nos eosinófilos recrutados para o sítio inflamatório; enquanto que o tratamento com o CAY10471, diminuiu o número de eosinófilos infiltrantes na cavidade pleural, mas não inibiu a biogênese de corpúsculos lipídicos nessas poucas células recrutadas. In vitro, eosinófilos humanos purificados estimulados com PGD2 tiveram a síntese de LTC4 inibida tanto pelo pré-tratamento com BWA868c, quanto pelo prétratamento com CAY10471. Além disso, a ativação do receptor DP1, com seu agonista seletivo (BW245c) e a ativação do receptor DP2 com o agonista seletivo do receptor DP2 (DK-PGD2) corroborou a observação de que no processo de síntese de LTC4 nos eosinófilos, ambos os receptores são necessáior, pois somente quando ambos os receptores foram ativados simultaneamente foi observada síntese de LTC4 nos corpúsculos lipídicos recém-formados (Eicosacell). Além disso, caracterizamos que uma das vias de sinalização intracelular envolvida na formação de corpúsculos lipídicos é depende da ativação de proteína quinase A (PKA). Em um outro grupo de ensaios, investigamos a PGD2 como potencial alvo terapêutico em doenças alérgicas. Recentemente, foi descrito que o extrato aquoso de C. sympodialis e a warafteína (alcalóide isolado) têm propriedades antialérgicas, visto que não somente reduzem a eosinofilia, mas também, a biogênese de corpúsculos lipídicos, assim como a produção de leucotrienos cisteinados. Dessa forma, aqui demonstramos que os pré-tratamentos tanto com o extrato quanto com o alcalóide isolado, foram capazes de inibir a produção de PGD2 ocorrida durante a resposta alérgica. In vitro, embora a warafteína não tenha inibido a biogênese de corpúsculos lipídicos em eosinófilos induzida por PGD2, observamos que é capaz de bloquear a liberação de PGD2 por mastócitos ativados – mas, não a produção de PGE2 por macrófagos ativados com A23187 – demonstrando que o mecanismo de ação dos seus efeitos antiinflamatórios não parecem envolver antagonismo de receptores em eosinófilos, e sim inibição da síntese da PGD2 em sítios alérgicos.
During allergic response, among several lipid mediators produced, prostaglandin D2 (PGD2) has emerged as key mediator. In addition to its known eosinophilotatics effects, recently PGD2 was described to be able to promote eosinophil activation, inducing lipid bodies biogenesis and LTC4 synthesis within these newly formed organelles. These effects are attributed to the action of PGD2 on its 2 receptors – DP1 e DP2 – which are expressed constituvely on eosinophil cell membranes. So, the main objective of this study was to identify the PGD2 specific receptor involved in LTC4 synthesis mechanism by stimulated eosinophils with PGD2. In vivo, in a murine allergic model of pleurisy and in a pleurisy induced by PGD2, the use of selective DP1 receptor (BWA868c) and DP2 receptor (CAY10471) antagonists showed us that both treatments inhibited LTC4 synthesis during these inflammatory responses. However, only BWA868C treatment was able to inhibit lipid bodies biogenesis within recruited eosinophils to the inflammatory sites, while CAY10471, decreased the number of infiltrated eosinophils in the pleural cavity, but did not inhibit lipid bodies biogenesis within these low number of recruited cells. In vitro, pre-treatment with BWA868c or CAY10471 inhibited LTC4 synthesis by human eosinophils stimulated with PGD2. Moreover, the activation of DP1 receptor with its selective agonist (BW245c) and DP2 activation with DP2 selective agonist (DK-PGD2) reinforced the observation that during LTC4 synthesis within eosinophils, activation of both receptors are necessary, because only simultaneous activation of DP1 and DP2, induced LTC4 synthesis within eosinophilic lipid bodies (Eicosacell). Moreover, we observed that the pathway of cellular signaling involved on lipid bodies biogenesis induced by DP1 activation is dependent on protein kinase A (PKA). In another set of experiments, we investigated PGD2 as a therapeutical target of allergic diseases. Recently, it was described that aqueous extract of C.sympodialis and warafteine (isolated alkaloid) have antiallergic properties, because of its effects on the reduction of eosinophils recruitment, lipid bodies biogenesis and cysteinyl leukotrienes synthesis. Here, we demonstrated that pre-treatments with extract and its alkaloid were able to inhibit PGD2 production during allergic response. In vitro, warafteine did not inhibit eosinophil lipid bodies biogenesis induced by PGD2, but it was capable to inhibit PGD2 release by activated mast cells – otherwise fail to blockade PGE2 production by A23187- activated macrophages – suggesting that the action mechanism of its antiinflammatory effects could occur through PGD2 synthesis inhibition in allergic sites.

by William, Wai-lun Lam.
Thesis (M.Phil.)--Chinese University of Hong Kong, 1993.
Includes bibliographical references (leaves 85-95).
Chapter I. --- Introduction --- p.1
Chapter II. --- Our Approach --- p.9
Chapter III. --- Results and Discussion - Synthetic Strategy --- p.29
Chapter IV. --- Results and Discussion - Pharmacological Activity --- p.44
Chapter V. --- Conclusion --- p.49
Chapter VI. --- Further Development --- p.53
Chapter VII. --- Experimental Section --- p.55
Chapter VIII. --- References --- p.85
Chapter IX. --- Supplementary Materials --- p.96

by Ho Wai Chan.
Thesis (Ph.D.)--Chinese University of Hong Kong, 1997.
Includes bibliographical references (p. [254]-271).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Mode of access: World Wide Web.
Abstract in Chinese.

Thesis (M.S.)--University of Tennessee, Knoxville, 2009.
Title from title page screen (viewed on Oct. 22, 2009). Thesis advisor: F. Neal Schrick. [Alpha] in title is subscript. Vita. Includes bibliographical references.

碩士
高雄醫學院
醫學研究所
85
In this study, we examined the pharmacological action of five calcium channel blockers (amlodipine, diltiazem, flunarizine, nifedipine, verapamil) oncompound 48/80 induced prostaglandin D2 and leukotriene C4/D4/E4 biosynthesisof peritoneal mast cell. Our data have indicated that preincubation of fivecalcium channel blockers possessed variant inhibitory effects on compound48/80 induced leukotrienes C4/D4/E4 and prostaglandin D2 biosynthesis from mastcells. In comparison, the inhibitory effect of amlodipine on leukotrienesC4/D4/E4 biosynthesis is more significant. And flunarizine inhibit prostaglandinD2 biosynthesis is more significant. In order to determine the role of calcium channel blockers on mediated secretion, the intracellular c-AMP and c-GMP levels of mast cell were measure by Amersham EIA kit. Calcium channel blockers exhibited concentration-dependentmanner to increase of these intracellular secondary messengers. Among fivecalcium channel blockers, flunarizine has shown a potent effect in the increaseof intracellular c-GMP level. And amlodipine exhibit a significant effect inthe increase of intracellular c-AMP level. And the modification of IP3 levelwas determined by Du- Pont RIA kit. Calcium channel blockers exhibited dose-dependent inhibitory effect on IP3 generation. In comparison, amlodipine and nifedipine possess a more significant inhibitory effect on the IP3 generation.In this study, we further characterized the mechanisms that regulate theactivation of rat mast cells response to calcium channel blocker. We suggestedthat calcium channel blockers may through modulate intracellular secondarymessenger (IP3, c-AMP, c-GMP) pathway to influence leukotrienes C4/D4/E4 andprostaglandin D2 biosynthesis on rat peritoneal mast cell.

Balding causes widespread psychological distress but is poorly controlled. The commonest treatment, minoxidil, was originally an antihypertensive drug that promoted unwanted hair. We hypothesized that another serendipitous discovery, increased eyelash growth side-effects of prostamide F(2alpha)-related eyedrops for glaucoma, may be relevant for scalp alopecias. Eyelash hairs and follicles are highly specialized and remain unaffected by androgens that inhibit scalp follicles and stimulate many others. Therefore, we investigated whether non-eyelash follicles could respond to bimatoprost, a prostamide F(2alpha) analog recently licensed for eyelash hypotrichosis. Bimatoprost, at pharmacologically selective concentrations, increased hair synthesis in scalp follicle organ culture and advanced mouse pelage hair regrowth in vivo compared to vehicle alone. A prostamide receptor antagonist blocked isolated follicle growth, confirming a direct, receptor-mediated mechanism within follicles; RT-PCR analysis identified 3 relevant receptor genes in scalp follicles in vivo. Receptors were located in the key follicle regulator, the dermal papilla, by analyzing individual follicular structures and immunohistochemistry. Thus, bimatoprost stimulates human scalp follicles in culture and rodent pelage follicles in vivo, mirroring eyelash behavior, and scalp follicles contain bimatoprost-sensitive prostamide receptors in vivo. This highlights a new follicular signaling system and confirms that bimatoprost offers a novel, low-risk therapeutic approach for scalp alopecias.