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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.
11

The influence of phosphodiesterase inhibitor, rolipram, on plasma tumor necrosis factor-gas levels and haemodynamics in lipopolysaccharide-treated rats /

Dutta, Prasannajit, January 2000 (has links)
Thesis (M.Sc.)--Memorial University of Newfoundland, Faculty of Medicine, / Typescript. Bibliography: leaves 44-68.
12

Efeitos do carbonato de lodenafila na consolidaÃÃo de fraturas da diÃfise femoral de Ratos tratados com haste intramedular / Effects of lodenafil carbonate on femoral diaphysis fractures healing in rats treated with intramedullary stem.

Gisele FaÃanha Diogenes Teixeira 26 February 2010 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O objetivo do estudo foi verificar os efeitos do carbonato de lodenafil no processo de consolidaÃÃo Ãssea nos fÃmures de ratos reduzidos com fio de Kirshner. Os fatores vasculares sÃo extremamente importantes para a formaÃÃo do calo Ãsseo. O carbonato de lodenafil causa efeitos vasodilatadores, pertence ao grupo dos inibidores da fosfodiesterase seletiva para o tipo 5 (PDE5), enzima que hidrolisa monofosfato de guanosina cÃclico (GMPc). O GMPc induz o relaxamento da musculatura lisa, sendo utilizado no tratamento da disfunÃÃo erÃtil. Foram utilizados 36 ratos machos, adultos, da linhagem Wistar, com o peso mÃdio de 300g. Todos os animais foram submetidos a cirurgia em que era realizada a fratura da diÃfise femoral com uma guilhotina romba. Os animais foram divididos em 2 grupos: o grupo lodenafil, que recebeu, via oral, doses diÃrias de carbonato de lodenafil (10mg/kg) e o grupo controle. Os animais foram sacrificados com 7, 14 e 28 dias de pÃs-operatÃrio. Houve duas mortes, dois falsos trajetos do fio e em trÃs animais nÃo foi estabelecida a fratura. Foram realizados estudo radiogrÃfico com filme de mamÃgrafo para analisar a densidade Ãptica e Ãrea do calo Ãsseo, medida em mm e estudo histolÃgico, utilizando amostras coradas com picrosirius red sob a luz poralizada do microscÃpio, para quantificar a formaÃÃo de colÃgeno tipo I e tipo III na regiÃo cortical prÃxima a fratura e no calo Ãsseo. A densidade de colÃgeno tipo I na regiÃo cortical do fÃmur prÃximo à fratura verificada no grupo lodenafil foi significantemente menor que a observada no grupo controle com 28 dias de consolidaÃÃo Ãssea (**P = 0,0028). Os resultados encontrados nÃo sÃo consistentes o suficiente para afirmar que este fÃrmaco exerce algum efeito na consolidaÃÃo Ãssea. Verificou-se que o Carbonato de lodenafil nÃo influenciou no processo de consolidaÃÃo Ãssea nos fÃmures de ratos reduzidos com fio de Kirshner. / The study was to investigate the effects of Lodenafil Carbonate in the process of bone healing in femurs of rats with reduced KirshnerÂs wire. The vascular factors are extremely important for the formation of callus. Lodenafil Carbonate cause vasodilatory effects, belongs to the group of selective phosphodiesterase type 5(PDE5) inhibitors, that enzyme inhibits cyclic guanosine monophosphate (GMPc) and relaxation of smooth muscles and are used to treat erectile dysfunction. It used 36 male rats, adult male rats, with the average weight of 300g. All animals underwent surgery in which fractures to the femoral shaft with a blunt guillotine. The animals were divided into 2 groups: lodenafil group, wich received oral doses of carbonate lodenafil (10mg/kg) and the control group. The animals were sacrificed at 7, 14 and 28 days postoperatively. There were two deaths, two false paths of the wire and three animals was not established fracture. Were performed radiographic studies with film mammography to analyze the optical density and area of callus, measured in mm  and histological study, using samples stained with picrosirius red under microscope light polarization, to quantify formation of collagen type I and type III in the cortical region near the fracture and callus. The density of type I collagen in the cortical region of the femur near the fracture observed in group lodenafil was significantly lower than that observed in the control group at 28 days of bone (** P = 0.0028). The results are not consistent enough to say that this drug has an effect on bone healing. It was found that the carbonate lodenafil not influence the process of bone healing in femurs of rats with reduced wire Kirshner.
13

Estudo da ação do inibidor de fosfodiesterase (sildenafil) no diabetes insipidus induzido pelo lítio / Role of phosphodiesterase inhibitor(sildenafil) in lithium-induced diabetes insipidus

Sanches, Talita Rojas Cunha 26 November 2008 (has links)
Os pacientes que usam lítio (Li) para tratamento do transtorno bipolar freqüentemente apresentam poliúria e deficiência de concentração urinária, sintomas do Diabetes Insipidus nefrogênico (DIN). Animais tratados com Li apresentam baixos níveis de produção de adenosina monofosfato cíclico (AMPc) em resposta ao hormônio antidiurético (HAD). O Sildenafil (Sil), um inibidor da fosfodiesterase 5 (PDE5), eleva os níveis intracelulares de guanosina monofosfato cíclico (GMPc), levando a inserção de aquaporina 2 (AQP2) na membrana plasmática das células do ducto coletor. Portanto, inibidores de PDE podem promover a inserção de AQP2 na membrana plasmática mesmo sem a ativação do receptor de HAD, indicando a participação de uma via alternativa mediada pelo GMPc. Nós investigamos o efeito do Sil na expressão renal das proteínas de membrana AQP2, UT-A1, NKCC2, NHE3, P-ENaC em ratos com DIN induzido pelo Li. Ratos Wistar foram divididos nos seguintes grupos: grupo controle, recebendo dieta alimentar normal durante quatro semanas; grupo Li, recebendo dieta alimentar normal com 40 mmol Li por quilo de dieta durante quatro semanas; grupo Li + Sil, recebendo dieta alimentar normal com 40 mmol Li por quilo de dieta durante quatro semanas e 200 mg por quilo de dieta de Sil a partir da segunda semana; grupo Sil, recebendo dieta alimentar normal durante a primeira semana e a partir da segunda semana recebendo dieta normal com 200 mg de Sil por quilo de dieta. Os animais do grupo Li desenvolveram poliúria, diminuição da osmolalidade urinária e diminuição da expressão da AQP2. No grupo Li+Sil, o Sil foi capaz de reverter parcialmente a poliúria, diminuir o clearance de água livre, aumentar a osmolalidade urinária e aumentar a expressão da AQP2. A expressão de UTA1 foi completamente normalizada com o tratamento com Sil. A expressão das proteínas NKCC2 e NHE3 apresentaram-se aumentadas no grupo tratado com Li, e o Sil não foi capaz de reverter tal alteração. Além disso, o tratamento com Sil reverteu completamente o aumento da resistência vascular renal. Assim, concluímos que o tratamento com Sil em ratos com DIN melhora a poliúria, aumenta a smolalidade urinária e diminui o clearance de água livre pelo aumento da expressão de AQP2 e UT-A1. O tratamento com Sil pode ser benéfico para pacientes que sofrem com DIN induzida pelo Li. / Patients taking lithium to treat bipolar disorder often present polyuria and urinary concentrating defect. In addition, lithium-treated animals present lower cyclic adenosine monophosphate production in response to vasopressin. Sildenafil (Sil), a phosphodiesterase 5 (PDE5) inhibitor, elevates intracellular cyclic guanosine monophosphate (cGMP) levels, leading to plasma membrane accumulation of aquaporin 2 (AQP2). Therefore, PDE inhibitors might induce AQP2 membrane insertion even without vasopressin receptor activation by activating a parallel cGMP-mediated signal transduction pathway. We investigated the effect of sildenafil on renal expression of AQP2, UT-A1, sodium/hydrogen exchanger (NHE3), type 1 bumetanide-sensitive Na-K-2Cl cotransporter (NKCC2), and the epithelial sodium channel alpha subunit (P-ENaC). Wistar rats received lithium (40 mmol/kg food) or not for 4 weeks (Li or control), some rats also receiving sildenafil (200 mg/kg food) in weeks 2-4, with or without lithium (Li+Sil or Sil). In Li+Sil rats, urine output was markedly lower, as was water free clearance, whereas urine osmolality was higher. Semiquantitative immunoblotting revealed the following: AQP2 expression was partially normalized; UT-A1 expression was completely normalized; expression of NKCC2 and NHE3 was significantly higher in Li rats (although not significantly different between Li+Sil rats and Li rats); and P-ENaC protein expression was unaltered in all groups. Sildenafil treatment completely reversed the lithium-induced increase in renal vascular resistance. In conclusion, sildenafil treatment of lithium-induced nephrogenic diabetes insipidus (NDI) improves polyuria, increases urinary osmolality, and decreases free water clearance via upregulation of renal AQP2 and UT-A1. Sildenafil treatment could be beneficial in patients with lithium-induced NDI.
14

Benefícios e riscos da testosterona para tratamento de desejo sexual hipoativo de mulheres: uma revisão crítica da literatura referente às décadas pré e após o advento dos inibidores da fosfodiesterase tipo 5 / Benefits and risks of testosterone treatment for hypoactive sexual desire in women: a critical review of the literature related to the decades before and after the advent of Phosphodiesterase type 5 inhibitors

Reis, Sandra Léa Bonfim 16 September 2013 (has links)
Introdução: Vários são os fatores que alteram a atividade sexual de homens e mulheres. Com o envelhecimento observa-se aumento das queixas de desejo hipoativo feminino e de disfunção erétil. Visto que o homem e sua parceira constituem um sistema dinâmico, antes do advento dos inibidores da fosfodiesterase eles se adaptavam às condições disfuncionais do casal. A eficácia aliada a poucos efeitos colaterais e à facilidade de administração da sildenafila e, posteriormente, da vardenafila e tadalafila, revolucionou o tratamento da disfunção erétil. Por outro lado, até a presente data, a terapêutica medicamentosa com testosterona para o desejo sexual hipoativo de mulheres, ainda gera controvérsias. Objetivo: Avaliar o uso de androgênio, utilizado para tratamento das queixas de desejo sexual hipoativo em mulheres, comparando dois períodos, ou seja, pré e após o aparecimento iPDE 5. Os efeitos colaterais e as divergências em relação a este tratamento também serão analisados. Método: Foram selecionados estudos em inglês, português e espanhol, publicados entre 1988 e os dias atuais, ou seja, na década pré-advento dos inibidores da fosfodiesterase 5 e após. A busca dos artigos foi feita em periódicos indexados nas bases Lilacs, Cochrane, Embase e Medline/PubMed, utilizando-se os seguintes descritores e suas combinações: sexualidade (sexuality), desejo sexual hipoativo em mulheres (female hypoactive sexual desire disorder), testosterona (testosterone), terapia androgênica em mulheres (androgen therapy in women). Discussão: Embora haja evidência sobre a efetividade do tratamento com testosterona para desejo hipoativo em mulheres, este uso ainda gera muitas controvérsias. Resultados: O número de estudos randomizados sobre uso de testosterona para tratamento de DSH feminino aumentou de 10%, comparando o período compreendido entre 1988 e 1998, para 90% entre 1999 e 2012. Todos os estudos randomizados analisados demonstraram benefícios sobre a resposta sexual, melhorando a libido, a excitação e/ou o orgasmo. Porém, como tiveram seguimento por um período máximo de 24 semanas, os riscos dessa administração não foram esclarecidos. Conclusão: A partir de 1988, ou seja, após a liberação comercial dos inibidores da fosfodiesterase do tipo 5, para tratamento da disfunção erétil, houve um aumento significativo do número de pesquisas com a finalidade de avaliar o uso de testosterona em mulheres com desejo hipoativo. Porém, ainda são necessários estudos de longo prazo para que os riscos e os benefícios, desta administração, sejam esclarecidos / Introduction: There are several factors that alter the sexual activity of both men and women. With age, an increase in complaints about hypoactive feminine desire and erectile dysfunction can be observed. Since the man and his partner constitute a dynamic system, before the advent of phosphodiesterase inhibitors, they would adapt to the dysfunctional conditions of the couple. The efficacy with few collateral effects and the easy administration of sildenafil and later, vardenafil and tadalafil, has revolutionized the treatment of erectile dysfunction. On the other hand, until now, the drug therapy with testosterone for hypoactive sexual desire of women still generates controversies. Objective: Assess the use of androgen, used for treating complaints of hypoactive sexual desire in women, comparing two periods, that is, before and after the emergence of iPDE 5. Side effects and divergences regarding this treatment are also analyzed. Method: Studies in English, Portuguese and Spanish were selected, published between 1988 and the present, that is, in the decade before the advent of phosphodieterase 5 inhibitors and after this fact. The search for papers was made in indexed journals on Lilacs, Cochrane, Embase and Medline/PubMed data bases, using the following descriptors and their combinations: sexuality, female hypoactive sexual desire disorder, testosterone or androgen therapy in women. Discussion: Although there is evidence on the effectiveness of treatment with testosterone for hypoactive desire in women, this use still generates many controversies. Results: The number of randomized studies on the use of testosterone for the treatment of female HSD has increased 10%, comparing the period between 1988 and 1998, to 90% between 1999 and 2012. All randomized studies analyzed showed benefits on the sexual response, improving libido, excitation and/or orgasm. However, since they were followed for a maximum of 24 weeks, the risks of this dosage were not clarified. Conclusion: From 1988, that is, after the commercial release of phosphodiesterase type 5 inhibitors, for the treatment of erectile dysfunction, there was a significant increase in the number of papers with the purpose of evaluating the use of testosterone in women with hypoactive desire. However, there is the need of long-term studies in order to clarify the risks and benefits of this use
15

Efeito agudo do inibidor da fosfodiesterase tipo 5 (sildenafil) na pressão sanguínea arterial durante e após exercício em pacientes submetidos a transplante cardíaco / Acute effects of a single dose of phosphodiesterase type 5 inhibitor (sildenafil) on systemic arterial blood pressure during and after exercise in heart transplant recipients.

Garlipp, Veridiana Moraes D'Avila Damas 11 June 2008 (has links)
Introdução: A hipertensão arterial sistêmica (HA) pode estar associada à diminuição na produção e liberação do óxido nítrico derivado do endotélio (NO). O uso do sildenafil leva ao aumento de monofosfato de guanosina cíclica (GMPc), um importante mediador de NO. Contudo, pouco se sabe sobre os efeitos da inibição da fosfodiesterase tipo 5 (PDE5) na monitorização da pressão arterial 24-h (MAPA), pressão arterial durante exercício, noraepinefrina (Nor) e capacidade ao exercício, principalmente após transplante de coração (TX). Métodos: Nós estudamos 22 pacientes pós TX, os quais foram randomizados, tomando dose única de sildenafil (50mg) ou placebo (50mg), aproximadamente uma hora antes de iniciar o protocolo. No dia 1, os pacientes realizaram avaliação clínica, teste cardiopulmonar de caminhada de seis minutos (TES) seguido de teste de esforço cardiopulmonar (TE), Após o término dos testes em esteira, foi colocado o MAPA. Determinamos em repouso (rep), último minuto do TES (6) e pico do TE (Ex): FC (bpm) PAS e PAD (mmHg), VO2(ml/kg/min), Slope VE/VCO2, tempo de exercício (TE, min), distância (TES, Km) e Nor (pg/ml). No dia 2 o protocolo foi repetido, realizando-se o cross-over. Dezessete pacientes apresentavam HA. Resultados: (Pl e Sil respectivamente), Sil reduziu (p<0.05): PAS-rep(138±7 vs 122±18); PAD-rep(83±12 vs 78±12); PAS-6(156± 20 vs 137± 22); PAD-6(82±13 vs 77±14); PAS-Ex(155± 27vs 124±36); PAD-Ex(79±16 vs 66± 16); PAS 24-h(121±10 vs 114±9), PAD 24-h(80±6 vs 76±5), PAS vigília(122±11 vs 115±9), PAD vigília(81± 6 vs 76±5) e PAS noturna(119±12 vs 112±10), PAD noturna(78±7 vs 73±8); e aumentou Nor-repouso(483±165 vs 622±211). Sil não alterou rep, 6 e EX: FC, VO2 e Slope. Conclusão: O ciclo NO-cGMP parece desempenhar papel importante no controle da pressão arterial em TX. Sendo que, a inibição da PDE5 parece apresentar efeitos benéficos no controle da hipertensão arterial em TX, podendo ser utilizada concomitantemente a terapia anti-hipertensiva usual. / Background: Systemic hypertension (SH) can be associated with a decrease in endothelium-dependent nitric oxide (NO). Sildenafil determines increment in cyclic guanosine monophosphate (cGMP) that a mediator of NO. However, little is known about the effects of PDE5 inhibition on 24-hour ambulatory (ABP) and exercise blood pressure, noreprinephrine (Nor) and exercise capacity, specially after heart transplantation (HT). Methods: We studied 22 HT pts that on the 1st day underwent a cardiopulmonary (CP) self-controlled treadmill 6walk test(6) and, after, an ECG monitored CP treadmill maximal exercise test(Ex) within 60 and 90 min after oral Sildenafil (Sil,50mg) or placebo(Pl) given at random, and ABP. We determined at basal position(b), last min of 6 and the peak Ex the HR(bpm), SBP and DBP (mmHg), VO2(ml/kg/min), Slope VE/VCO2, exercise time(ET, min), distance(D, Km) and Nor(pg/ml). Also, after CP tests 24-h SBP and DBP were monitored. It was repeated on the 2nd day when the cross-over was done. Seventeen pts had SH. Results: (Pl and Sil respectively), Sil reduced (p<0.05): b- SBP(138±7 vs 122±18); b-DBP(83±12 vs 78±12); 6-SBP(156± 20 vs 137± 22); 6-DBP(82±13 vs 77±14); Ex-SBP(155± 27vs 124±36); Ex-DBP(79±16 vs 66± 16); 24-h SBP(121±10 vs 114±9) and DBP(80±6 vs 76±5), daytime SBP(122±11 vs 115±9) and DBP(81± 6 vs 76±5) and nighttime SBP(119±12 vs 112±10) and DBP(78±7 vs 73±8); and increase b-Nor(483±165 vs 622±211). Sil did not change in b, 6 and EX; HR, Nor, VO2 and Slope. Conclusion: NO-cGMP pathway seems to play a role in blood pressure control in HT. The PDE5 inhibition could have potential beneficial effects on hypertensive HT in addition to antihypertensive therapy.
16

Efeito agudo do inibidor da fosfodiesterase tipo 5 (sildenafil) na pressão sanguínea arterial durante e após exercício em pacientes submetidos a transplante cardíaco / Acute effects of a single dose of phosphodiesterase type 5 inhibitor (sildenafil) on systemic arterial blood pressure during and after exercise in heart transplant recipients.

Veridiana Moraes D'Avila Damas Garlipp 11 June 2008 (has links)
Introdução: A hipertensão arterial sistêmica (HA) pode estar associada à diminuição na produção e liberação do óxido nítrico derivado do endotélio (NO). O uso do sildenafil leva ao aumento de monofosfato de guanosina cíclica (GMPc), um importante mediador de NO. Contudo, pouco se sabe sobre os efeitos da inibição da fosfodiesterase tipo 5 (PDE5) na monitorização da pressão arterial 24-h (MAPA), pressão arterial durante exercício, noraepinefrina (Nor) e capacidade ao exercício, principalmente após transplante de coração (TX). Métodos: Nós estudamos 22 pacientes pós TX, os quais foram randomizados, tomando dose única de sildenafil (50mg) ou placebo (50mg), aproximadamente uma hora antes de iniciar o protocolo. No dia 1, os pacientes realizaram avaliação clínica, teste cardiopulmonar de caminhada de seis minutos (TES) seguido de teste de esforço cardiopulmonar (TE), Após o término dos testes em esteira, foi colocado o MAPA. Determinamos em repouso (rep), último minuto do TES (6) e pico do TE (Ex): FC (bpm) PAS e PAD (mmHg), VO2(ml/kg/min), Slope VE/VCO2, tempo de exercício (TE, min), distância (TES, Km) e Nor (pg/ml). No dia 2 o protocolo foi repetido, realizando-se o cross-over. Dezessete pacientes apresentavam HA. Resultados: (Pl e Sil respectivamente), Sil reduziu (p<0.05): PAS-rep(138±7 vs 122±18); PAD-rep(83±12 vs 78±12); PAS-6(156± 20 vs 137± 22); PAD-6(82±13 vs 77±14); PAS-Ex(155± 27vs 124±36); PAD-Ex(79±16 vs 66± 16); PAS 24-h(121±10 vs 114±9), PAD 24-h(80±6 vs 76±5), PAS vigília(122±11 vs 115±9), PAD vigília(81± 6 vs 76±5) e PAS noturna(119±12 vs 112±10), PAD noturna(78±7 vs 73±8); e aumentou Nor-repouso(483±165 vs 622±211). Sil não alterou rep, 6 e EX: FC, VO2 e Slope. Conclusão: O ciclo NO-cGMP parece desempenhar papel importante no controle da pressão arterial em TX. Sendo que, a inibição da PDE5 parece apresentar efeitos benéficos no controle da hipertensão arterial em TX, podendo ser utilizada concomitantemente a terapia anti-hipertensiva usual. / Background: Systemic hypertension (SH) can be associated with a decrease in endothelium-dependent nitric oxide (NO). Sildenafil determines increment in cyclic guanosine monophosphate (cGMP) that a mediator of NO. However, little is known about the effects of PDE5 inhibition on 24-hour ambulatory (ABP) and exercise blood pressure, noreprinephrine (Nor) and exercise capacity, specially after heart transplantation (HT). Methods: We studied 22 HT pts that on the 1st day underwent a cardiopulmonary (CP) self-controlled treadmill 6walk test(6) and, after, an ECG monitored CP treadmill maximal exercise test(Ex) within 60 and 90 min after oral Sildenafil (Sil,50mg) or placebo(Pl) given at random, and ABP. We determined at basal position(b), last min of 6 and the peak Ex the HR(bpm), SBP and DBP (mmHg), VO2(ml/kg/min), Slope VE/VCO2, exercise time(ET, min), distance(D, Km) and Nor(pg/ml). Also, after CP tests 24-h SBP and DBP were monitored. It was repeated on the 2nd day when the cross-over was done. Seventeen pts had SH. Results: (Pl and Sil respectively), Sil reduced (p<0.05): b- SBP(138±7 vs 122±18); b-DBP(83±12 vs 78±12); 6-SBP(156± 20 vs 137± 22); 6-DBP(82±13 vs 77±14); Ex-SBP(155± 27vs 124±36); Ex-DBP(79±16 vs 66± 16); 24-h SBP(121±10 vs 114±9) and DBP(80±6 vs 76±5), daytime SBP(122±11 vs 115±9) and DBP(81± 6 vs 76±5) and nighttime SBP(119±12 vs 112±10) and DBP(78±7 vs 73±8); and increase b-Nor(483±165 vs 622±211). Sil did not change in b, 6 and EX; HR, Nor, VO2 and Slope. Conclusion: NO-cGMP pathway seems to play a role in blood pressure control in HT. The PDE5 inhibition could have potential beneficial effects on hypertensive HT in addition to antihypertensive therapy.
17

Benefícios e riscos da testosterona para tratamento de desejo sexual hipoativo de mulheres: uma revisão crítica da literatura referente às décadas pré e após o advento dos inibidores da fosfodiesterase tipo 5 / Benefits and risks of testosterone treatment for hypoactive sexual desire in women: a critical review of the literature related to the decades before and after the advent of Phosphodiesterase type 5 inhibitors

Sandra Léa Bonfim Reis 16 September 2013 (has links)
Introdução: Vários são os fatores que alteram a atividade sexual de homens e mulheres. Com o envelhecimento observa-se aumento das queixas de desejo hipoativo feminino e de disfunção erétil. Visto que o homem e sua parceira constituem um sistema dinâmico, antes do advento dos inibidores da fosfodiesterase eles se adaptavam às condições disfuncionais do casal. A eficácia aliada a poucos efeitos colaterais e à facilidade de administração da sildenafila e, posteriormente, da vardenafila e tadalafila, revolucionou o tratamento da disfunção erétil. Por outro lado, até a presente data, a terapêutica medicamentosa com testosterona para o desejo sexual hipoativo de mulheres, ainda gera controvérsias. Objetivo: Avaliar o uso de androgênio, utilizado para tratamento das queixas de desejo sexual hipoativo em mulheres, comparando dois períodos, ou seja, pré e após o aparecimento iPDE 5. Os efeitos colaterais e as divergências em relação a este tratamento também serão analisados. Método: Foram selecionados estudos em inglês, português e espanhol, publicados entre 1988 e os dias atuais, ou seja, na década pré-advento dos inibidores da fosfodiesterase 5 e após. A busca dos artigos foi feita em periódicos indexados nas bases Lilacs, Cochrane, Embase e Medline/PubMed, utilizando-se os seguintes descritores e suas combinações: sexualidade (sexuality), desejo sexual hipoativo em mulheres (female hypoactive sexual desire disorder), testosterona (testosterone), terapia androgênica em mulheres (androgen therapy in women). Discussão: Embora haja evidência sobre a efetividade do tratamento com testosterona para desejo hipoativo em mulheres, este uso ainda gera muitas controvérsias. Resultados: O número de estudos randomizados sobre uso de testosterona para tratamento de DSH feminino aumentou de 10%, comparando o período compreendido entre 1988 e 1998, para 90% entre 1999 e 2012. Todos os estudos randomizados analisados demonstraram benefícios sobre a resposta sexual, melhorando a libido, a excitação e/ou o orgasmo. Porém, como tiveram seguimento por um período máximo de 24 semanas, os riscos dessa administração não foram esclarecidos. Conclusão: A partir de 1988, ou seja, após a liberação comercial dos inibidores da fosfodiesterase do tipo 5, para tratamento da disfunção erétil, houve um aumento significativo do número de pesquisas com a finalidade de avaliar o uso de testosterona em mulheres com desejo hipoativo. Porém, ainda são necessários estudos de longo prazo para que os riscos e os benefícios, desta administração, sejam esclarecidos / Introduction: There are several factors that alter the sexual activity of both men and women. With age, an increase in complaints about hypoactive feminine desire and erectile dysfunction can be observed. Since the man and his partner constitute a dynamic system, before the advent of phosphodiesterase inhibitors, they would adapt to the dysfunctional conditions of the couple. The efficacy with few collateral effects and the easy administration of sildenafil and later, vardenafil and tadalafil, has revolutionized the treatment of erectile dysfunction. On the other hand, until now, the drug therapy with testosterone for hypoactive sexual desire of women still generates controversies. Objective: Assess the use of androgen, used for treating complaints of hypoactive sexual desire in women, comparing two periods, that is, before and after the emergence of iPDE 5. Side effects and divergences regarding this treatment are also analyzed. Method: Studies in English, Portuguese and Spanish were selected, published between 1988 and the present, that is, in the decade before the advent of phosphodieterase 5 inhibitors and after this fact. The search for papers was made in indexed journals on Lilacs, Cochrane, Embase and Medline/PubMed data bases, using the following descriptors and their combinations: sexuality, female hypoactive sexual desire disorder, testosterone or androgen therapy in women. Discussion: Although there is evidence on the effectiveness of treatment with testosterone for hypoactive desire in women, this use still generates many controversies. Results: The number of randomized studies on the use of testosterone for the treatment of female HSD has increased 10%, comparing the period between 1988 and 1998, to 90% between 1999 and 2012. All randomized studies analyzed showed benefits on the sexual response, improving libido, excitation and/or orgasm. However, since they were followed for a maximum of 24 weeks, the risks of this dosage were not clarified. Conclusion: From 1988, that is, after the commercial release of phosphodiesterase type 5 inhibitors, for the treatment of erectile dysfunction, there was a significant increase in the number of papers with the purpose of evaluating the use of testosterone in women with hypoactive desire. However, there is the need of long-term studies in order to clarify the risks and benefits of this use
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Estudo da ação do inibidor de fosfodiesterase (sildenafil) no diabetes insipidus induzido pelo lítio / Role of phosphodiesterase inhibitor(sildenafil) in lithium-induced diabetes insipidus

Talita Rojas Cunha Sanches 26 November 2008 (has links)
Os pacientes que usam lítio (Li) para tratamento do transtorno bipolar freqüentemente apresentam poliúria e deficiência de concentração urinária, sintomas do Diabetes Insipidus nefrogênico (DIN). Animais tratados com Li apresentam baixos níveis de produção de adenosina monofosfato cíclico (AMPc) em resposta ao hormônio antidiurético (HAD). O Sildenafil (Sil), um inibidor da fosfodiesterase 5 (PDE5), eleva os níveis intracelulares de guanosina monofosfato cíclico (GMPc), levando a inserção de aquaporina 2 (AQP2) na membrana plasmática das células do ducto coletor. Portanto, inibidores de PDE podem promover a inserção de AQP2 na membrana plasmática mesmo sem a ativação do receptor de HAD, indicando a participação de uma via alternativa mediada pelo GMPc. Nós investigamos o efeito do Sil na expressão renal das proteínas de membrana AQP2, UT-A1, NKCC2, NHE3, P-ENaC em ratos com DIN induzido pelo Li. Ratos Wistar foram divididos nos seguintes grupos: grupo controle, recebendo dieta alimentar normal durante quatro semanas; grupo Li, recebendo dieta alimentar normal com 40 mmol Li por quilo de dieta durante quatro semanas; grupo Li + Sil, recebendo dieta alimentar normal com 40 mmol Li por quilo de dieta durante quatro semanas e 200 mg por quilo de dieta de Sil a partir da segunda semana; grupo Sil, recebendo dieta alimentar normal durante a primeira semana e a partir da segunda semana recebendo dieta normal com 200 mg de Sil por quilo de dieta. Os animais do grupo Li desenvolveram poliúria, diminuição da osmolalidade urinária e diminuição da expressão da AQP2. No grupo Li+Sil, o Sil foi capaz de reverter parcialmente a poliúria, diminuir o clearance de água livre, aumentar a osmolalidade urinária e aumentar a expressão da AQP2. A expressão de UTA1 foi completamente normalizada com o tratamento com Sil. A expressão das proteínas NKCC2 e NHE3 apresentaram-se aumentadas no grupo tratado com Li, e o Sil não foi capaz de reverter tal alteração. Além disso, o tratamento com Sil reverteu completamente o aumento da resistência vascular renal. Assim, concluímos que o tratamento com Sil em ratos com DIN melhora a poliúria, aumenta a smolalidade urinária e diminui o clearance de água livre pelo aumento da expressão de AQP2 e UT-A1. O tratamento com Sil pode ser benéfico para pacientes que sofrem com DIN induzida pelo Li. / Patients taking lithium to treat bipolar disorder often present polyuria and urinary concentrating defect. In addition, lithium-treated animals present lower cyclic adenosine monophosphate production in response to vasopressin. Sildenafil (Sil), a phosphodiesterase 5 (PDE5) inhibitor, elevates intracellular cyclic guanosine monophosphate (cGMP) levels, leading to plasma membrane accumulation of aquaporin 2 (AQP2). Therefore, PDE inhibitors might induce AQP2 membrane insertion even without vasopressin receptor activation by activating a parallel cGMP-mediated signal transduction pathway. We investigated the effect of sildenafil on renal expression of AQP2, UT-A1, sodium/hydrogen exchanger (NHE3), type 1 bumetanide-sensitive Na-K-2Cl cotransporter (NKCC2), and the epithelial sodium channel alpha subunit (P-ENaC). Wistar rats received lithium (40 mmol/kg food) or not for 4 weeks (Li or control), some rats also receiving sildenafil (200 mg/kg food) in weeks 2-4, with or without lithium (Li+Sil or Sil). In Li+Sil rats, urine output was markedly lower, as was water free clearance, whereas urine osmolality was higher. Semiquantitative immunoblotting revealed the following: AQP2 expression was partially normalized; UT-A1 expression was completely normalized; expression of NKCC2 and NHE3 was significantly higher in Li rats (although not significantly different between Li+Sil rats and Li rats); and P-ENaC protein expression was unaltered in all groups. Sildenafil treatment completely reversed the lithium-induced increase in renal vascular resistance. In conclusion, sildenafil treatment of lithium-induced nephrogenic diabetes insipidus (NDI) improves polyuria, increases urinary osmolality, and decreases free water clearance via upregulation of renal AQP2 and UT-A1. Sildenafil treatment could be beneficial in patients with lithium-induced NDI.
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The effects of administration of a nuclear factor kappa-B inhibitor on pulmonary endothelial dysfunction after cardiopulmonary bypass: impact on oxygenation and hemodynamics and development of therapeutic and preventive modalities in a porcine model

Rosu, Cristian 01 1900 (has links)
Introduction: La circulation extracorporelle (CEC) peut entraîner une dysfonction endothéliale pulmonaire et l’hypertension pulmonaire. Le SN50 agit au niveau de la signalisation cellulaire pour prévenir ces réactions à la CEC et pourrait renverser la dysfonction endothéliale pulmonaire post-CEC sans effets néfastes sur l’hémodynamie. Méthodes: Quatre groups de porcs ont reçu un parmi quatre traîtements avant de subir 90 minutes de CEC et 60 minutes de reperfusion: (1) milrinone nébulisé; (2) sildenafil nébulisé; (3) placebo nébulisé; et (4) SN-50 intraveineux. Un monitoring hémodynamique invasif a été utilisé. La réactivité vasculaire des artères pulmonaires de deuxième ordre a été évaluée face à l’acétylcholine et la bradykinine. Résultats: Le sildénafil produit une augmentation significative de la pression de l’artère pulmonaire (PAP) moyenne à 60 minutes de reperfusion par rapport au début de la chirurgie. Les relaxations dépendantes de l’endothélium face à la bradykinine étaient meilleurs dans les groupes milrinone et SN-50 et surtout dans le groupe sildénafil par rapport au groupe placébo. Le SN-50 produisait de moins bonnes relaxations dépendantes de l’endothélium face à l’acétylcholine que les autres traitements incluant placébo. Conclusion: Le sildénafil prévient mieux la dysfonction endothéliale pulmonaire que les autres traitements. Les bénéfices du SN-50 sont possiblement sous-estimés vu que la dose n’a pas pu être ajustée à la durée de CEC. Le sildenafil inhalé mérite une étude plus importante chez l’humain et le SN-50 dans un model de CEC animal. / Background: Cardiopulmonary bypass (CPB) can lead to pulmonary endothelial dysfunction and consequent pulmonary hypertension. The novel agent SN-50 acts at the level of the transduction pathway to prevent these responses and may limit or reverse post-CPB pulmonary endothelial dysfunction and pulmonary hypertension without the untoward effects on hemodynamics seen with other known therapies. Methods: Four groups of Landrace-Yorkshire swine that received one of four treatments before undergoing 90 minutes of normothermic CPB and 60 minutes of reperfusion were compared: (1) Nebulized milrinone; (2) nebulized sildenafil; (3) placebo consisting of nebulized NaCl solution; and (4) intravenous SN-50. Invasive hemodynamic monitoring was used throughout all experiments. Vascular reactivity of second-degree pulmonary arteries was evaluated in response to acetylcholine and bradykinin. Results: Sildenafil produced a significant increase in mean pulmonary artery pressure (PAP) at 60 minutes after CPB compared to baseline. Both the sildenafil and milrinone groups had increased mean PAP/MAP ratio at 60 minutes after CPB compared to baseline, however this ratio was not different between the groups. Endothelial-dependent relaxations to bradykinin were improved in the SN-50 and milrinone groups and especially the sildenafil group as compared to placebo. SN-50 produced worse endothelium-dependent relaxations in response to acetylcholine compared to the other groups including placebo. Conclusion: Sildenafil better prevented pulmonary endothelial dysfunction than all other treatments. The improvements seen with SN-50 may be suboptimal as dose could not be titrated to length of CPB. Inhaled sildenafil and SN-50 both merit further study in human trials and animal models, respectively.
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Rôle du monoxyde d'azote dans la calcification vasculaire et la rigidité artérielle dans un modèle d'hypertension systolique isolée

Gilbert, Liz-Ann 12 1900 (has links)
L’hypertension systolique isolée (HSI) est le résultat de changements au niveau de la paroi vasculaire qui ont pour conséquence d’augmenter la rigidité artérielle. Ces modifications surviennent surtout au niveau des grosses artères comme l’aorte et sont associées au vieillissement. La fragmentation des fibres élastiques, leur calcification (élastocalcinose) et la fibrose font partie des changements majeurs observés avec l’âge. En plus de ces changements, le vieillissement vasculaire provoque des modifications au niveau des cellules qui composent la paroi. Les cellules endothéliales sécrètent moins de monoxyde d’azote (NO) provoquant une dysfonction endothéliale et les cellules musculaires lisses vasculaires (CMLVs) synthétisent maintenant des protéines matricielles et osseuses. Situé entre le sang et les CMLVs, l’endothélium contrôle le tonus vasculaire par la sécrétion de plusieurs substances vasoactives qui interagissent entre elles afin de maintenir l’homéostasie du système vasculaire. Parmi celles-ci, on note l’endothéline (ET), un puissant vasoconstricteur et le NO, un gaz vasorelaxants. Ce dernier est aussi reconnu pour bloquer la production d’ET par un mécanisme dépendant du guanosine monophosphate cyclique (GMPc). Comme il y a une interaction entre le NO et l’ET, et que cette dernière est impliquée dans la calcification artérielle, le NO pourrait être impliqué dans la modulation de l’élastocalcinose et de la rigidité artérielle par l’inhibition de l’ET et la modification de la composition de la paroi. Cet effet, qui se produirait au delà des effets vasorelaxants du NO, offre un potentiel thérapeutique intéressant pour l’HSI. Afin d’évaluer l’implication du NO dans la calcification vasculaire et la rigidité artérielle, un modèle animal d’HSI a été utilisé (modèle warfarine vitamine K, WVK). Ce modèle d’élastocalcinose est basé sur l’inhibition de la maturation d’une protéine anti-calcifiante, la matrix Gla protein (MGP), par la warfarine. Afin de déterminer l’implication physiologique du NO dans l’initiation et la progression de l’élastocalcinose, sa production a été inhibée par un analogue de la L-arginine, le L-NG-nitroarginine methyl ester (L-NAME). Lors des processus d’initiation de la calcification, le L-NAME a prévenu l’élastocalcinose sans toutefois modifier la vitesse de l’onde de pouls (PWV). Suite au traitement L-NAME, l’expression de la NO synthase inductible (iNOS) a été diminuée alors qu’elle a été augmentée lors du traitement WVK. Elle pourrait donc être impliquée dans les processus de calcification vasculaire. De plus, la NO synthase endothéliale (eNOS) semble également impliquée puisqu’elle a été augmentée dans le modèle WVK. Cette hausse pourrait être bénéfique pour limiter l’élastocalcinose alors que l’expression de la iNOS serait délétère. Lors de la progression de la calcification, le L-NAME a augmenté l’élastocalcinose et le PWV. Dans ce contexte, l’ET serait impliquée dans l’amplification de la calcification vasculaire entrainant une hausse de la rigidité artérielle. Comme le NO endogène limite la progression de la calcification et conséquemment la rigidité artérielle, il semble être protecteur. L’efficacité d’une modulation de la voie du NO dans le modèle WVK a été étudiée par l’administration d’un donneur de NO, le sinitrodil, ou d’un inhibiteur de la phosphosdiestérase 5 (PDE5), le tadalafil. La modulation de la voie du NO semble être bénéfique sur la rigidité artérielle, mais seulement de façon aiguë. En effet, le sinitrodil a modifié de transitoirement la rigidité au niveau de l’aorte possiblement par la modulation du tonus vasculaire sans toutefois avoir des effets sur la composition de la paroi. Comme le modèle WVK n’affecte pas la fonction endothéliale, les concentrations endogènes de NO semblent être optimales puisque le sinitrodil provoque une augmentation de l’élastocalcinose possiblement par le développement d’une tolérance. Tout comme le sinitrodil, le tadalafil a modulé de manière aiguë la rigidité artérielle sans modifier la composition de la paroi. Globalement, ces travaux ont permis de mettre en évidence les effets bénéfiques du NO endogène pour limiter le développement de l’HSI, suggérant qu’une dysfonction endothéliale, tel qu’observé lors du vieillissement, a un impact négatif sur la maladie. / Isolated systolic hypertension (ISH) is the result of complex changes in the vascular wall and consequently the increase of arterial stiffness. These modifications occur mainly in conductance arteries, like the aorta, and are associated with aging. The fragmentation of elastic fibers, calcification (elastocalcinosis), and fibrosis are major changes with age. In addition to these changes in the extracellular matrix, vascular aging also induces vascular cell wall modifications. These include decreased production of nitric oxide (NO) by endothelial cells, which induces endothelial dysfunction, and the production of matrix and bone proteins by vascular smooth muscle cells (VSMCs). Located between the blood and VSMCs, the endothelium controls vascular tone by secreting various vasoactive factors. These factors interact with each other to maintain the hemodynamic of the vascular system. Among these factors, the vasoconstrictor endothelin (ET) and the vasodilator NO. The latter has been shown to block ET production via a cyclic guanosine monophosphates-(cGMP) dependent mechanism, whereas ET has been implicated in arterial calcification. Therefore, NO might be involved in the modulation of elastocalcinosis and arterial stiffness by inhibiting ET and modifying the vascular wall composition. This effect of NO could offer interesting therapeutic potential for ISH. To evaluate the implication of NO in the vascular calcification and arterial stiffness, an animal model of ISH was used. This model of elastocalcinosis is based on the inhibition of the maturation of the anti-calcific protein, matrix Gla protein (MGP), by warfarin (WVK model). To gain insight into the physiological role of endogenous NO in the initiation and progression of elastocalcinosis, its production was inhibited by the administration of L-NAME. Interestingly, elastocalcinosis was prevented by L-NG-nitroarginine methyl ester (L-NAME) administration without any modifications of the pulse wave velocity (PWV) during the initiation of the calcification processes. After the L-NAME treatment, the expression of inducible NO synthase (iNOS) was decreased, whereas upon treatment with warfarin alone the expression of iNOS was increased, which could be implicated in vascular calcification and arterial stiffness. In addition, endothelial NO synthase (eNOS) seems to be implicated in this process as its expression was also increased upon WVK treatment. This increase could be beneficial to limit elastocalcinosis, whereas the increase in iNOS expression could be harmful. L-NAME administration during the progression of calcification increased elastocalcinosis and PWV. In an endothelial dysfunction context, ET has been shown to be involved in the amplification process of vascular calcification causing an increase in arterial stiffness. As NO limits the progression of calcification and consequently arterial stiffness, endogenous NO seems to be protective in the aorta. The efficacy of exogenous modulation of the NO pathway in the WVK model was studied upon administration of the NO donor, sinitrodil, or the phosphodiesterase type 5 inhibitor (PDE5), tadalafil. The exogenous modulation of the NO pathway seemed to be beneficial for arterial stiffness, but only in an acute manner. Indeed, sinitrodil modified the acute stiffness in the aorta potentially by vascular tone modulation, without having any effect on vascular wall composition. Since endothelial function was not affected upon WVK model, endogenous NO concentrations seem to be optimal. Thus, exogenous NO potentially caused an increase of elastocalcinosis by inducing tolerance to NO. As well as sinitrodil, tadalafil modulated the arterial stiffness in an acute manner without modifying the composition of the vascular wall. Broadly, these studies provide evidence that endogenous NO can limit ISH development, suggesting that endothelial dysfunction, as observed in aging, has a negative impact on this pathology.

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