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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.
111

Avaliação dos mecanismos determinantes dos efeitos cardiovasculares promovidos pelo IM-7 em ratos com hipertensão induzida pelo L-NAME : abordagens in vivo e in vitro / Evaluation of determinant mechanisms involved in cardiovascular effects induced by IM-7 in L-NAME hypertensive rats: In vivo and in vitro approaches

Anjos, Raline Mendonça dos 30 August 2010 (has links)
Made available in DSpace on 2015-05-14T13:00:14Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2331593 bytes, checksum: 773c3f24392a37cc5990eecb7f6f2761 (MD5) Previous issue date: 2010-08-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Imidazolidinic derivates present a wide range of biological activities, such as anti-arrhythmic and anti-hypertensive. The vasorelaxant effect of six Imidazolinic compounds was evaluated in this study. Among of this, the cardiovascular effects induced by IM-7 were evaluated using in vivo and in vitro assays. HPA-01 and IM-3 produced a reduced relaxation of rat mesenteric artery rings contracted by phenylephrine (PHE) (MR = 43.15 ± 7.69%; MR = 54.08 ± 6.59%, respectively). IM-6 e IM-2 showed vasoconstictor effects in rigns with endothelium and vasorelaxant effect when endothelium was removed. Meanwhile, HPA-02 did not induce significant vasorelaxant effect. In normotensive non-anesthetized rats, the pretreatment with L-NAME or hexamethonium did not affect the hypotensive and bradicardic effects induced by IM-7. In isolated rat atrial preparations from normotensive, IM-7 (1pM-1 mM) produced negative chronotropic (MR = 65.45 ± 11.4%; pD2 = 3.94 ± 0.02) and inotropic (MR = 68.58 ± 8,0% ; pD2 = 6.74 ± 0.05) effects. which were attenuated by atropine. In hypertensive non-anesthetized rats IM-7 (1, 5, 10, 20 e 30 mg/Kg, i.v.) induced hypotensive and bradicardic effects. These effects were abolished after pre-treatment with atropine (2 mg/Kg, i.v.). In isolated hypertensive rat mesenteric artery rings IM-7 (1pM-1 mM), elicited concentration-dependent relaxation of PHE-induced contraction (pD2 = 5.64  0.09). After removal of the vascular endothelium IM-7 effects were significantly attenuated (pD2 = 3.8 ± 0.07 p < 0.001), suggesting the participation of endothelium derived relaxant factors in the IM-7 induced vasorelaxant effect. Similar results were obtained in the presence of L-NAME (100 M), ODQ (10μM), or atropine (100 nM). In endothelium denuded rings incubed with KCl 20 mM the relaxant response was not attenuated. Furthermore, in absence of extracellular calcium, IM-7 concentration-dependently depressed the vasoconstrictions derived from CaCl2. Similar results were obtained in contractions induced by 5-HT, cumulative administration of PHE or Na3VO4. These results demonstrate that IM-7 induced best pharmacological profile comparing with the other imidazolidinic derivatives. In normotensive rats, the inotropic e chronotropic effects induced by IM-7 are probably due to activation of muscarinic receptors. In hypertensive rats, the hypotensive, bradicardic and vasorelaxant effects seem to involve muscarinic receptor activation. Furthermore, IM-7 exerts a vasorelaxant effect by inhibiting calcium influx and contractile apparatus. / Derivados imidazolidínicos apresentam uma ampla variedade de atividades biológicas, dentre elas a antiarrítmica e anti-hipertensiva. O efeito vasorerrelaxante de seis derivados hidantoínicos foi avaliado neste estudo. Dentre estas substâncias, os efeitos cardiovasculares induzidos por IM-7 foram avaliados empregando-se abordagens in vivo e in vitro. Em anéis de artéria mesentérica superior de rato, as substâncias HPA-01 e IM-3 apresentaram discreto efeito vasorrelaxante. Concentrações cumulativas de IM-2 e IM-6 induziram vasoconstrição e vasorrelaxamento na presença e na ausência do endotélio, respectivamente, enquanto HPA-02 não causou efeitos significativos. Em ratos normotensos não anestesiados, o bloqueio com hexametônio ou com L-NAME não foi capaz de alterar os efeitos hipotensor e bradicárdico induzidos por IM-7. Em átrio isolado de rato, este derivado hidantoínico causou efeitos cronotrópico (Emáx = 65,45 ± 11,4% ; pD2 = 3,94 ± 0,02 ) e inotrópico (Emáx = 68,58 ± 8,0% ; pD2 = 6,74 ± 0,05 ) negativos, que foram atenuados na presença da atropina. Em ratos com hipertensão L-NAME não-anestesiados, IM-7 (1, 5, 10, 20 e 30 mg/Kg, i.v.) induziu hipotensão e bradicardia, os quais foram abolidos na presença da atropina (2 mg/Kg, i.v.). Em artéria mesentérica superior isolada de rato hipertenso, IM-7 induziu vasorrelaxamento em anéis pré-contraídos com fenilefrina (FEN) (pD2 = 5,64  0,09) e esse efeito foi significantemente atenuado após a remoção do endotélio (pD2 = 3,8 ± 0,07 p < 0,001), sugerindo a participação de fatores relaxantes endoteliais. Resultados similares foram obtidos após a incubação de L-NAME (100 M), ODQ (10 M) ou atropina (100 nM). Em anéis sem endotélio, incubados com KCl 20 mM, o vasorrelaxamento induzido por IM-7 não foi atenuado. IM-7 reduziu contrações induzidas por 80 mM de KCl em anéis sem endotélio (pD2 = 3,84 ± 0,05) de maneira similar ao observado em contrações induzidas por fenilefrina. Concentrações isoladas de IM-7 (10-5, 10-4 e 10-3) reduziram significativamente as contrações induzidas por CaCl2. Resultados similares foram observados nas contrações induzidas por serotonina (5-HT) e pela administração cumulativa de FEN ou Na3VO4. As contrações transientes induzidas por FEN (10 M) não foram alteradas. Estes resultados demonstram que dentre os derivados hidantoínicos avaliados, IM-7 apresentou melhor atividade farmacológica. Em ratos normotensos, os efeitos inotrópicos e cronotrópicos negativos induzidos por esta substância, possivelmente decorrentes da ativação muscarínica, justificam a bradicardia observada em estudos anteriores. O vasorrelaxamento independente de endotélio provavelmente é decorrente da atuação desta substância sobre a maquinaria contrátil na musculatura lisa vascular. Em ratos hipertensos, IM-7 induziu hipotensão, bradicardia e vasorrelaxamento provavelmente de origem muscarínica. Além disso, este derivado hidantoínico também parece ser capaz de inibir o influxo de cálcio e atuar na maquinaria contrátil para promover vasodilatação
112

Efeitos da dobutamina ou levosimendana nas variáveis cardiopulmonares após a dexmedetomidina em pôneis submetidos à hipotensão pelo isoflurano / Effects of dobutamine or levosimendan on cardiopulmonary variables after dexmedetomidine in isoflurane-induced hypotension in ponies

Cavalcanti, Ruben Lundgren January 2016 (has links)
Isoflurano reduz o débito cardíaco e produz vasodilatação periférica resultando em hipotensão sistêmica. Hipotensão pode contribuir para morbidade e mortalidade em equinos. Queda na pressão sanguínea pode ser tratada com inotrópicos e/ou vasopressores. Levosimendana é um inotrópico sensibilizador de cálcio que produz aumento na contratilidade e diminuição na resistência vascular periférica. Dexmedetomidina é um agonista de receptor adrenérgico α2 que aumenta a resistência vascular periférica. Este estudo objetivou avaliar os efeitos cardiopulmonares da dobutamina versus levosimendana após infusão de dexmedetomidina em pôneis com hipotensão induzida pelo isoflurano. Dez pôneis saudáveis (média 13,9 ± DP 2,4 anos) foram anestesiados com detomidina, seguido por quetamina e midazolam e mantidos em um estado hipotensivo induzido por um nível profundo de anestesia com isoflurano (2 CAM). Os animais foram randomizados para receber dexmedetomidina e dobutamina (DD; n=5) ou dexmedetomidina e levosimendana (DL; n=5). Após 45 minutos do estado estável de hipotensão, as variáveis basais foram registradas. Dexmedetomidina foi administrada em 10 minutos (3,5 μg.Kg-1) e as variáveis foram registradas; em seguida, infusão contínua de dexmedetomidina iniciou (1,75 μg.Kg-1.hr-1) e as variáveis foram registradas após 45 minutos. Dobutamina (5 μg.Kg-1.min-1) ou levosimendana (12 μg.Kg-1) foram administradas e as variáveis foram registradas após 10 minutos, seguido por ITC de dobutamina ou de levosimendana (0,2 μg.Kg-1.min-1) com novo registro das variáveis após 45 minutos. Por fim, as infusões foram interrompidas e as variáveis foram registradas após 45 minutos. Isoflurano (2 CAM) reduziu as PAs, o IS e o IC, mas não afetou o IRVS. Em relação ao isoflurano, bolus de dexmedetomidina aumentou as PAs pelo aumento do IRVS e da PVC, mas não afetou o IS e o IC previamente reduzidos pelo isoflurano. Após 45 minutos, dexmedetomidina elevou a PMAP, o VD/VT, o lactato e a creatinina e reduziu as PAs, o IRVS e a FC, mas não afetou o IC. Dexmedetomidina também reduziu o CaO2, a PaO2, a Pv̅O2, a Sv̅O2, o Cv̅O2, a Hb e o ḊO2I em ambos grupos em relação ao tempo basal. Dobutamina e levosimendana aumentaram significativamente o IS e o IC, mas dobutamina aumentou as PAs, o IRVS, o IRVP, a PMAP, a PVC, o CaO2, o Cv̅O2, a Hb, o ḊO2I e reduziu a creatinina e a O2ER, enquanto levosimendana não afetou as PAs, reduziu a PVC e o IRVS e aumentou o VD/VT e o Q̇s/Q̇t. Infusão de dexmedetomidina causa prejuízos cardiopulmonares importantes a despeito de aumentar as PAs após dose em bolus IV durante hipotensão induzida pelo isoflurano em pôneis. Dobutamina é melhor alternativa que levosimendana para restaurar as funções cardiovasculares e manter oxigenação durante infusão de dexmedetomidina associada a dose alta de isoflurano em pôneis. / Isoflurane decreases cardiac output and produces peripheral vasodilation resulting in systemic hypotension. Hypotension may contribute to morbidity and mortality in equines. Drop in blood pressure can be treated with inotropic and or vasopressors. Levosimendan is a calcium sensitizer that produces increase in contractility and decrease in systemic vascular resistance. Dexmedetomidine is an α2 adrenergic-receptor agonist that increases systemic vascular resistance. This study aimed to evaluate the cardiopulmonary effects of dobutamine versus levosimendan after infusion of dexmedetomidine on isoflurane-induced hypotension in ponies. Ten healthy ponies (mean 13,9 ± SD 2,4 years) were anesthetized with detomidine followed by ketamine and midazolam and maintained at a steady hypotensive state induced by a deep level of isoflurane anesthesia (2 MAC). Animals were randomized to receive dexmedetomidine and dobutamine (DD; n=5) or dexmedetomidine and levosimendan (DL; n=5). After 45 min of steady state, baseline variables were recorded. Dexmedetomidine was administered over 10 minutes (3,5 μg.Kg-1), and variables were recorded; thereafter, dexmedetomidine CRI started (1,75 μg.Kg-1.hr-1), and variables were recorded after 45 minutes. Dobutamine (5 μg.Kg-1.min-1) or levosimendan (12 μg.Kg-1) were administered over 10 minutes and variables were recorded, followed by dobutamine or levosimendan CRI (0,2 μg.Kg-1.min-1) for 45 minutes, then variables were recorded a sixth time. Lastly, infusions were interrupted and the variables were again recorded after 45 minutes. Isoflurane (2 MAC) decreased arterial blood pressures (ABPs), SI and CI, but not affected SVR. In relation to isoflurane, bolus of dexmedetomidine increased ABPs due to augmentation on RVS and PCV, but not affected SI and CI already reduced by isoflurane. After 45 minutes, dexmedetomidine raised MPAP, VD/VT, lactate and creatinine and reduced ABPs, SVR, and HR, but not affected CI. Dexmedetomidine also reduced CaO2, PaO2, Pv̅O2, Sv̅O2, Cv̅O2, Hb and ḊO2I in both groups compared to baseline. Dobutamine and levosimendan increased SI and CI, but dobutamine increased ABPs, SVRI, PVRI, MPAP, CVP, CaO2, Cv̅O2, Hb, ḊO2I and decreased creatinine and O2ER, while levosimendan not affected ABPs, decreased CVP and SVRI and increased VD/VT and Q̇s/Q̇t. Dexmedetomidine CRI during isoflurane-induced hypotension in ponies causes statistically significant cardiopulmonary effects regardless of increasing the ABPs after bolus administration. Dobutamine is better alternative than levosimendan for restoring cardiovascular function and maintaining oxygenation during CRI dexmedetomidine associated with high-dose isoflurane in ponies. Because the proposed vasoconstriction model produced late opposite physiological effect, further studies with levosimendan in ponies and horses remain to be performed, especially in clinical patients. Likewise, further studies are justified to evaluate the effect of levosimendan on regional tissue perfusion.
113

Acute Affects of a Walking Workstation on Ambulatory Blood Pressure in Prehypertensive Adults

January 2013 (has links)
abstract: INTRODUCTION: Exercise performed at moderate to vigorous intensities has been shown to generate a post exercise hypotensive response. Whether this response is observed with very low exercise intensities is unclear. PURPOSE: To compare post physical activity ambulatory blood pressure (ABP) response to a single worksite walking day and a normal sedentary work day in pre-hypertensive adults. METHODS: Participants were 7 pre-hypertensive (127 + 8 mmHg / 83 + 8 mmHg) adults (3 male, 4 female, age = 42 + 12 yr) who participated in a randomized, cross-over study that included a control and a walking treatment. Only those who indicated regularly sitting at least 8 hours/day and no structured physical activity were enrolled. Treatment days were randomly assigned and were performed one week apart. Walking treatment consisted of periodically increasing walk time up to 2.5 hours over the course of an 8 hour work day on a walking workstation (Steelcase Company, Grand Rapids, MI). Walk speed was set at 1 mph. Participants wore an ambulatory blood pressure cuff (Oscar 2, SunTech Medical, Morrisville, NC) for 24-hours on both treatment days. Participants maintained normal daily activities on the control day. ABP data collected from 9:00 am until 10:00 pm of the same day were included in statistical analyses. Linear mixed models were used to detect differences in systolic (SBP) and diastolic blood pressure (DBP) by treatment condition over the whole day and post workday for the time periods between 4 -10 pm when participants were no longer at work. RESULTS:BP was significantly lower in response to the walking treatment compared to the control day (Mean SBP 126 +7 mmHg vs.124 +7 mmHg, p=.043; DBP 80 + 3 mmHg vs. 77 + 3 mmHg, p = 0.001 respectively). Post workday (4:00 to 10:00 pm) SBP decreased 3 mmHg (p=.017) and DBP decreased 4 mmHg (p<.001) following walking. CONCLUSION: Even low intensity exercise such as walking on a walking workstation is effective for significantly reducing acute BP when compared to a normal work day. / Dissertation/Thesis / M.S. Exercise and Wellness 2013
114

Efeito da hidratação na resposta da pressão arterial pós-exercício e seus mecanismos / Effects of hydration on post-exercise blood pressure response and mechanisms

Fernando da Silveira Lobo 24 March 2011 (has links)
Os efeitos da hidratação sobre a pressão arterial (PA) e seus mecanismos hemodinâmicos e autonômicos pós-exercício foram pouco estudados e os resultados são controversos. Esse estudo avaliou esses efeitos, em normotensos jovens após uma sessão de exercício aeróbico. Assim, 16 rapazes submeteram-se a quatro sessões experimentais, realizadas em ordem aleatória: controle sem hidratação, exercício sem hidratação, controle com hidratação e exercício com hidratação. Nas sessões com hidratação, os sujeitos ingeriam 1l de água na noite anterior, 500ml 60min antes da intervenção (exercício ou repouso) e mais 1ml por 1g de massa corporal perdida logo após a intervenção. O exercício foi realizado por 45min em ciclo ergômetro em 50% do VO2pico. Em todas as sessões as PA sistólica (S), média (M) e diastólica (D), o débito cardíaco (DC), a frequência cardíaca (FC) e as variabilidades da FC e da PA foram medidos antes e após as intervenções. O exercício diminuiu a PAS e o volume sistólico (VS) e impediu os aumentos da FC, da PAD, da PAM e da sensibilidade baroreflexa, que ocorreram na sessão controle. A hidratação não modificou as respostas hemodinâmicas e autonômicas após o exercício. Em conclusão, em sujeitos jovens normotensos, a hidratação não modificou o efeito hipotensor promovido pelo exercício aeróbico no período de recuperação, não afetando seus mecanismos hemodinâmicos e autonômicos / The effects of hydration on post-exercise blood pressure (BP) and hemodynamic and autonomic mechanisms were poorly studied and results are controversial. This study evaluated these effects in young normotensives after an acute bout of aerobic exercise. Sixteen young men underwent four sessions in a random order: control without hydration, exercise without hydration, control with hydration and exercise with hydration. In the hydration sessions, subjects drank 1l of water in the night before, 500 ml 60 min before the intervention (rest or exercise) and 1ml for 1g of body mass lost immediately after the intervention. In exercise sessions, they exercised for 45 min on a cycle ergometer at 50% of VO2peak. Systolic (S), diastolic (D) and mean (M) BP, as well as cardiac output (CO), heart rate (HR), and HR and BP variabilities were measured before and after the interventions. Exercise produced a significant reduction in SBP and stroke volume (SV), and abolished the increase in HR, DBP, MBP and baroreflex sensitivity that occurred in the control sessions. Hydration did not change hemodynamic and autonomic responses after exercise. In conclusion, in healthy young subjects, hydration did not modify the hypotensive effect promoted by the aerobic exercise during the recovery period, not affecting its hemodynamic and autonomic mechanisms
115

RepresentaÃÃes sociais de pacientes renais crÃnicos sobre a hipotensÃo arterial / Representation theory the pacient chronic renal disease with hypotension

Fernanda Celedonio de Oliveira 12 November 2009 (has links)
CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / A doenÃa renal CrÃnica està sendo considerada patologia de carÃter progressivo e importante problema de saÃde publica. O nÃmero de pessoas mantidas nas diversas modalidades de diÃlise no Brasil aumenta consideravelmente. Nesse tempo, inÃmeras complicaÃÃes podem ocorrer, entre elas a hipotensÃo arterial, que acomete 25% das sessÃes de hemodiÃlise. O estudo objetivou conhecer as representaÃÃes sociais sobre a hipotensÃo arterial de pacientes com InsuficiÃncia Renal CrÃnica em tratamento de hemodiÃlise e comparar entre os homens e as mulheres. A pesquisa do tipo exploratÃria descritiva de natureza quanti qualitativa com suporte na Teoria das RepresentaÃÃes Sociais foi realizada no perÃodo de marÃo a maio de 2009 em uma clÃnica de hemodiÃlise de Fortaleza conveniada ao SUS. Os sujeitos constituÃdos de 50 pacientes renais crÃnicos que apresentavam hipotensÃo arterial durante o tratamento de hemodiÃlise foram submetidos a uma abordagem com multimÃtodos e a coleta de dados realizada nos prontuÃrios, com estÃmulos indutores no Teste de AssociaÃÃo livre de palavras e por meio da entrevista narrativa e colagens. A organizaÃÃo dos dados quantitativos, do prontuÃrio e das associaÃÃes livres de palavras, foram realizadas por meio das planilhas do programa Excel, enquanto os dados qualitativos, entrevista narrativa e as colagens, se efetuaram pelas linhas narrativas (Spink) e tÃcnica de expressÃo, respectivamente. Foram respeitados os preceitos Ãticos-legais conforme a ResoluÃÃo N 196/96 que normatiza a pesquisa com seres humanos . Os resultados mostraram que houve predomÃnio do sexo feminino; faixa etÃria entre os maiores de 60 anos; analfabetos; casados; catÃlicos; aposentados; renda familiar em torno de um salÃrio mÃnimo e com procedÃncia da Capital, com o predomÃnio do HAS e DM como causas prevalentes entre eles. Evocaram 200 palavras que foram selecionadas quanto ao nÃcleo central e perifÃrico. Nas entrevistas narrativas, 30 sujeitos participaram, sendo identificadas sete categorias. Por fim, 45 deles utilizaram as colagens, classificando-as em 13 categorias especificas. Percebemos que os homens, as representaÃÃes sociais sÃo mais pessimistas e negativas; associaram a HA com suor, o medo e a vista ruim e morte; descreveram que, apÃs o inÃcio do tratamento, as limitaÃÃes impostas pela doenÃa dificultaram a maneira de viver, alegaram mudanÃas na realizaÃÃo de atividades desenvolvidas anteriormente; associaram as limitaÃÃes da doenÃa com a falta de liberdade, prisÃo e fogo. As representaÃÃes sociais da mulheres foram expressas de maneira mais cautelosa e sentimentalista; associaram a HA com suor; medo e vista ruim e dor; relataram atitudes positivas, o bom convÃvio com a doenÃa; os aspectos religiosos e os planos futuros como consequÃncias voltadas para enfrentamento da doenÃa e objeto de superaÃÃo; predominaram imagens compartilhadas sobre as dificuldades na convivÃncia com os novos hÃbitos alimentares, mas ressaltando o poder de conformidade. ConcluÃmos que hà muito a fazer pelos pacientes renais crÃnicos, bem como pelos profissionais que deles cuidam, pois, conhecendo a singularidade de cada individuo, serà possÃvel aplicar os princÃpios da promoÃÃo da saÃde com vistas a uma melhor qualidade de vida. / The chronic renal disease is considered a progressive pathology and an important public health problem. In Brazil, the number of patients undergoing any of the different dialysis modalities keeps growing. During the dialysis sessions, countless complications may occur, such as arterial hypotension, which occurs in 25% of the sessions. This study was aimed to screen the representation by gender within the chronic renal disease patient population with hypotension episodes during hemodialysis. The study was carried out between March and May 2009, using a descriptive, exploratory, quantitative and qualitative methodology based on the Social Representation Theory. The study was done at a hemodialysis clinic in the City of Fortaleza serving the state-run health service (SUS), over a population of 50 chronic renal patients suffering from arterial hypotension episodes during dialysis. Data were obtained from the patients clinical history by a multi-method approach, a free association of words with inducing stimuli, narrative interviews and collages. Data obtained from the clinical histories and from the free association of words were organized in Excel spreadsheets, while the qualitative data, i.e. the interview and collage, were organized by narrative lines (Spink) and the expression technique, respectively. All legal and ethics norms were followed pursuant to Resolution 196/96, which regulates the research on human beings. The results show a dominance of women, an age range of over 60 years, illiterate, married, catholic, retired, patients with a family income of about one minimum wage, residents of the capital city, mainly with HAS and DM as the cause for dialysis. They evoked 200 words, chosen regarding the central core and periphery. 30 patients were interviewed and were classified in 7 categories. Finally, 45 patients used the collage and were classified into 13 categories. We noticed that the social representations are more pessimistic and negative in men. They associated AH to sweating, fear, bad sight and death, and reported that after the initiation of treatment the limitations imposed by the illness made their daily life more difficult. They also reported changes in previously developed activities and associated the illness limitations to a lack of freedom, prison and fire. The social representations of women were expressed in a more cautious and sentimental way. They associated AH to sweating, fear, bad sight and pain. They reported positive attitudes, dealt well with the condition, and mentioned religious aspects and future plans as tools to face and overcome the illness. Shared images related to the difficulties related to the new dietary habits were common, yet highlighting their ability to come to terms with it. We concluded that many things can be done for chronic renal patients as well as for the professionals taking care of them. By knowing the particularities of each individual, it would be possible to apply healthcare promotion principles aimed to improve the patients quality of life.
116

Avaliação do risco de hipotensão arterial durante a indução de raquianestesia em pacientes tratados cronicamente com fármacos antihipertensivos

Mondino, Ludimila Nunes Zini 06 April 2017 (has links)
Submitted by Biblioteca da Faculdade de Farmácia (bff@ndc.uff.br) on 2017-04-06T17:41:50Z No. of bitstreams: 1 Mondino, Ludimila Nunes Zini [Dissertação, 2011].pdf: 1717903 bytes, checksum: 167e0d17af2be8b361975e28691728cb (MD5) / Made available in DSpace on 2017-04-06T17:41:50Z (GMT). No. of bitstreams: 1 Mondino, Ludimila Nunes Zini [Dissertação, 2011].pdf: 1717903 bytes, checksum: 167e0d17af2be8b361975e28691728cb (MD5) / A Raquianestesia com bupivacaína isobárica 0,5% (BP) é amplamente utilizada para cirurgia ortopédica de artroplastia primária de quadril (AQ), e a hipotensão Arterial é uma das complicações mais freqüentes desta técnica. O objetivo deste estudo foi quantificar a incidência de hipotensão arterial em pacientes submetidos à AQ e identificar fatores de risco independentes associados ao aumento da incidência de hipotensão após a indução da raquianestesia. Estudo de caso-controle, realizado com a análise de 937 (100%) registros de anestesia de pacientes de ambos os sexos, com uso de BP e idade igual ou superior a 40 anos. De acordo com os critérios pré-definido de "hipotensão arterial" (diminuição da pressão arterial média (PAM) maior que 30% do valor da PAM na pré-indução ou quando a PAM for inferior a 70mmHg), o evento foi detectado em 35,3% (n = 284) dos pacientes incluídos na análise. O risco relativo para hipotensão em pacientes que usam inibidores da ECA ou diuréticos é de 1,66 e 1,63 vezes, respectivamente. Por análise multivariada, idade (OR-1,034), hipertensão arterial (OR-2,44) e / ou diabetes melittus (OR- 17,14) foram independentemente associados com a ocorrência de hipotensão durante a indução da raquianestesia. / Spinal anesthesia with isobaric bupivacaine 0,5% (BP) is widely used for orthopedic surgery of primary hip arthroplasty (AQ), and the hypotension is one of the most frequent complications of this technique. The goal of this study was to quantify the incidence of hypotension in patients undergoing AQ and identify independent risk factors associated with increased incidence of hypotension after induction of anesthesia. Case-Control study was conducted, with the analysis of 937 (100%) anesthesia records of patients of both sexes, use of BP and age equal or greater than 40 years. According to the predefined criteria of "hypotension" (decrease > 30% of Mean arterial blood preassure (MAP) in the pre-induction or when MAP <70 mmHg), the event was detected in 35.3% (n = 284) of the patients included in the analysis. The relative risk for hypotension in patients who use ACE inhibitors or diuretics is 1.66 and 1.63 times respectively. By multivariate analysis, age (OR-1,034), hypertension (OR-2,44) and/or presence of diseases diabetes (OR-17,14) were independently associated with the occurrence of hypotension during induction of anesthesia.
117

Effects of the NO donors Sodium Nitroprusside andS-nitrosoglutathione on oxygen consumption and embryonic organ growth in the domestic broiler chicken,Gallus gallus domesticus.

Ekström, Andreas January 2010 (has links)
Nitric oxide (NO) is an important chemical factor that controls vascular tone in the cardiovascular system. NO is a vasodilatory molecule that plays a role in blood pressure and blood flow regulation as well as vessel formation and tissue cell proliferation. NO influences the flow by which nutrients and other metabolites required for growth are transported to the tissues. The aim of this study was to investigate if NO, through mediation by the NO donors Sodium Nitroprusside (SNP) and S-Nitrosoglutathione (GSNO) affect growth and oxygen consumption of prenatal broiler chicken. The results indicate that, although the treatments did not have clear significant effects on the embryos or the organs examined, a slight delay in development can be observed in the GSNO treatment embryos. The study could not conclude, however, if this was due to effects of NO donors
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Rôle du récepteur B2 de la Bradykinine dans un modèle murin de choc hémorragique contrôlé / Role of bradykinin B2 receptor in a mouse model of controlled hemorrhagic shock

Charbonneau, Hélène 24 October 2016 (has links)
Le système kinine-kallicréine (SKK) est un système peptidique vasoactif dont l'action vasodilatatrice est médiée par l'activation de deux récepteurs de la bradykinine (BK): le RB2 (constitutif) et le RB1 (inductible). Ils sont impliqués dans plusieurs fonctions physiologiques telles que la régulation locale et systémique de la pression artérielle, la volémie et la perméabilité vasculaire. Par ses interactions avec le système rénine-angiotensine (SRA), la BK participe aux effets thérapeutiques des inhibiteurs de l'enzyme de conversion (IEC). Le SKK joue un rôle encore mal connu dans le contrôle de la pression artérielle lors d'une anesthésie ou d'un état de choc, en particulier hémorragique.L'objectif de ce travail était d'étudier le rôle du RB2 dans l'hypotension artérielle et les dysfonctions d'organe induites par un choc hémorragique. Deux modèles murins de choc hémorragique contrôlé ont été utilisés: i) un modèle à pression contrôlée afin d'évaluer l'impact hémodynamique, ii) un modèle à volume contrôlé pour évaluer le retentissement sur la défaillance d'organe. Nous avons d'abord étudié l'impact du blocage du RB2 (par invalidation génique ou blocage pharmacologique) sur la sévérité de l'agression rénale aiguë et la perméabilité vasculaire rénale induite par un choc hémorragique à pression contrôlée. Dans ce modèle, le RB2 ne joue pas de rôle néphroprotecteur. Par contre, son blocage améliore la tolérance à l'hypotension et réduit la mortalité induite par le choc hémorragique. Nous avons ensuite étudié, dans un modèle comportant une exposition préalable à un IEC, l'impact hémodynamique du blocage pharmacologique du RB2 au cours d'un choc hémorragique à pression ou à volume contrôlé. En effet, l'imprégnation préalable par un IEC peut être à l'origine d'hypotensions artérielles réfractaires délétères pendant l'anesthésie et a fortiori en cas d'état de choc hémorragique. Nos résultats mettent en évidence que le blocage du RB2 juste avant le choc permet de limiter l'aggravation des hypotensions artérielles induite par les IEC et diminue la lactatémie. Dans cette même situation, nous avons étudié l'impact du blocage du RB2 sur la mortalité et la défaillance d'organe induites par un choc hémorragique à volume contrôlé. Nous avons montré que le blocage du RB2 réduit significativement la mortalité des souris préalablement traitées par un IEC par rapport aux souris sous IEC seul. Dans nos conditions expérimentales, le blocage du RB2 ne semble pas modifier l'impact hépatique, rénal et digestif du choc. En conclusion, le RB2 n'exerce pas spontanément de rôle néphroprotecteur au cours du choc hémorragique. Par contre, l'effet hémodynamique bénéfique de son blocage au cours d'un choc hémorragique indique que l'accumulation de BK participe à l'hypotension artérielle observée dans cette circonstance. Compte tenu des bénéfices en terme de mortalité, le blocage aigu du SKK par un antagoniste du RB2 mérite d'être étudié chez les patients traités au long cours par des inhibiteurs du SRA et qui nécessitent une prise en charge en urgence en anesthésie-réanimation. / The kallikrein-kinin system (SKK) is a peptide vasoactive system, its vasodilator action is mediated through activation of two G-protein coupled receptors (R) for bradykinin (BK): B2R (constitutive) and B1R (inducible). They are involved in many physiological functions such as local and systemic regulation of blood pressure, blood volume and vascular permeability. BK interacts with the renin-angiotensin system (RAS) and contributes to the therapeutic effects of angiotensin converting enzyme inhibitor (ACEI) and angiotensin II receptor antagonists. The SKK involvement in blood pressure control during anaesthesia or shock, especially during haemorrhage remains poorly documented. The aim of this study was to investigate the role of B2R in hypotension and organ dysfunction induced by haemorrhagic shock. Two models of controlled haemorrhagic shock in mice were used: i) a pressure controlled model to assess the hemodynamic impact, ii) a controlled volume model to assess the impact on the organ failure. We investigated first the effect RB2 blockade (by gene knockout or pharmacological blockade) on the severity of acute renal injury and changes in renal vascular permeability induced by a controlled pressure haemorrhagic shock. In this model, the B2R does not play a nephroprotective role. By contrast, B2R blockage improves low blood pressure tolerance and reduces mortality induced by haemorrhagic shock. Then, we investigated the hemodynamic effect of B2R blockage on pressure or volume controlled hemorrhagic shock models in ACEI-pretreated mice. In fact, ACEI can be associated with severe deleterious hypotension during anaesthesia as well as during haemorrhagic shock. We showed B2R blockade before hemorrhagic shock induction decreased the worsening of ACEI-induced arterial hypotension and decrease blood lactate. Finally, we investigated the impact of pharmacological blockade of B2R on mortality and multi-organs failure during volume controlled hemorrhagic shock model in ACEI-pre-treated mice. We showed blocking the B2R significantly reduces mortality in ACEI-pre-treated mice. However, under our experimental conditions, B2R blockade does not alter significantly the impact of hemorrhagic shock on liver, kidney and intestine. In conclusion, the B2R does not play a nephroprotective role in a murine hemorrhagic shock. However, the beneficial effect of B2R blockade points out the involvement of BK accumulation during hemorrhagic shock-induced hypotension. According to the benefits observed regarding mortality, acute SKK blockage using a B2R antagonist should be considered in patients treated by RAS blockers and that require emergency anaesthesia and intensive care.
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Obtenção de peptídeos vasoativos a partir do plasma de serpentes brasileiras (Bothrops jararaca e Crotalus durissus terrificus). / Obtention vasoactive peptides from the plasma of brazilian snakes (Bothrops jararaca e Crotalus durissus terrificus).

Sandra Alves Barreto 06 September 2006 (has links)
A Bradicinina, a mais importante das cininas plasmáticas, foi encontrada pela primeira vez em mamíferos. Pouco foi estudado sobre o sistema calicreína-cininas em serpentes, mas o que se sabe é que, provavelmente, são deficientes do Fator XII, um ativador da pré-calicreína em mamíferos. Com o objetivo de identificarmos novos peptídeos, submetemos plasmas das serpentes Bothrops jararaca (SBJ) e da Crotalus durissus terrificus (SCDT) tratados por duas metodologias simplificadas de determinação de bradicininogênio. O estudo com os plasmas das SBJ e da SCDT liberou uma substância com efeito semelhante à cinina de mamíferos que produziu hipotensão na serpente e no rato; esse efeito foi potencializado com o uso do captopril (0,05/0,010 mg/Kg), que inibe a cininase II, confirmando resultados diferentes das literaturas existentes sobre esse assunto. Com o resultado obtido, fracionamos este produto em aparelho de HPLC, e obtivemos seqüências peptídicas que não apresentaram homologia com a bradicinina. / The Bradykinin (BK), most important of the plasmatic kinins, was encountered for the first time in mammals. Little was studied in the kallikrein-kinin system in snakes, but it is known that, it is probably deficient of Factor XII, an activator of the daily prekallikrein in mammals. In order to identify new peptides, we submit plasma of the snakes Bothrops jararaca (SBJ) and e Crotalus durissus terrificus (SCDT) in two simplified methodologies for bradykininnogen determination, to analyze in bioassays of average arterial pressure of mammals and isolated ileum of guinea pig. The study with plasma of the SBJ and the SCDT showed that the kinin of mammals released a substance with effect similar to that producing hypotension in snakes and rats; this effect was potentiated with the use of captopril (0,05/0,010 mg/Kg), wich inhibits kininase II, confirming results different from literature?s obtained on this subject. With the obtained result, we fractioned this product in HPLC equipment and obtained peptides sequences with no homologie with the bradykinin.
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Tratamento convencional versus eletroacupuntura para reversão de hipotensão arterial em cavalos sob anestesia geral inalatória / Conventional versus electroacupuncture treatment for hypotesion reversion in horses under inhalation anesthesia

Franco, Elisabeth Cunha 26 March 2012 (has links)
Made available in DSpace on 2016-01-26T18:55:33Z (GMT). No. of bitstreams: 1 beth[1].pdf: 1005574 bytes, checksum: 2fa927c95f66ff65dd7b52a8dbeedd7a (MD5) Previous issue date: 2012-03-26 / This study aimed to evaluate the efficacy of dobutamine comparatively with electroacupuncture and sham treatment to reversion of isoflurano-induced hypotension in equine. Six adult horses were evaluated using a crossover design with at least 15 days between treatments. All the horses were medicated with xylazine (0.5mg kg-1) by intravenous administration (iv). Guaifenesin (100mg/kg iv) and thiopental (5mg kg-1 iv) were administered, following the inhalation anesthesia with isoflurane. The horses were positionated in left lateral recumbency and they were maintained in mechanical ventilation. After anesthesia was established, the isoflurane concentration was raised until mean blood pressure was maintained between 40 to 45mmHg. After that, the animals were treated with a constant rate of 1.5mg kg -1min-1 intravenously dobutamine (DOB), electroacupunture to PC6 acupoint (EA) and sham treatment (Sham). All the treatments were maintained for 60 minutes. Heart rate, cardiac rhythms, median arterial blood pressure, rectal temperature, arterial blood gases, creatine kinase (CK), aspartate transaminase (AST), recovery time and quality of recovery were investigated. The mean blood pressure increased 50%, 36.5% and 7.5%% in DOB, EA and Sham treatment, respectively. Higher values were observed in the DOB treatment when compared with Sham treatment at 10, 20, 30 and 40 minutes and at 20 minutes when compared with EA treatment. Heart rate, blood gases, CK, AST, recovery time and quality of recovery did not differ among the treatments. It was concluded that the dobutamine treatment was more effective than electroacupuncture and Sham tretament for the reversion of isoflurane induced hypotension in horses. / Este estudo objetivou avaliar a eficiência do tratamento da hipotensão arterial induzida pelo isofluorano em equinos, com dobutamina comparativamente à aplicação de estímulo elétrico no acuponto pericárdio 6 (PC6) e em ponto falso de acupuntura. Foram avaliados seis cavalos adultos, saudáveis, provenientes do Hospital Veterinário da Unoeste. Os mesmos animais foram avaliados nos três tratamentos, com intervalo de 15 dias entre cada experimento. A medicação pré-anestésica foi feita com xilazina (0,5mg kg-1) por via intravenosa (iv). A indução anestésica foi realizada com éter gliceril guaiacol (100mg kg-1 iv, 10%) em associação ao tiopental sódico (5mg kg-1 iv), com posterior manutenção em anestesia geral inalatória com isofluorano, em ventilação mecânica. Após a estabilização da anestesia foi induzida a hipotensão arterial, mediante o incremento da concentração de isofluorano, até a obtenção de pressão arterial média (PAM) entre 40 a 45 mmHg. A partir do estabelecimento da hipotensão, os animais foram submetidos a um dos tratamentos: DOB: dobutamina (1,5µg kg-1 min-1) em infusão contínua iv; EA: aplicação de estímulo elétrico no acuponto PC6 bilateralmente; Sham: aplicação de estímulo elétrico em ponto falso de acupuntura. Todos os tratamentos foram mantidos durante 60 minutos. Foram mensurados: frequência cardíaca (FC) e ritmo cardíaco, pressão arterial média (PAM), temperatura retal (T), fração inspirada e expirada de isofluorano (ETiso), concentração final expirada de dióxido de carbono (ETCO2) e variáveis hemogasométricas (PaO2, PaCO2, pH, HCO3-1), concentração sérica de aspartato aminotransferase (AST) e creatina fosfoquinase (CK), tempo e qualidade da recuperação pós-anestésica. Houve incremento na PAM de 50%, 36,6% e 7,5% nos grupos DOB, EA e Sham, respectivamente. Valores superiores de PAM foram observados no tratamento DOB em relação ao tratamento Sham aos 10, 20, 30 e 40 minutos e aos 20 minutos em relação ao tratamento EA. A FC, as variáveis hemogasométricas, as enzimas CK e AST, o tempo e a qualidade de recuperação pós-anestésica não diferiram entre os grupos. Concluí-se que o tratamento com dobutamina foi mais efetivo para reversão de hipotensão em cavalos sob anestesia inalatória quando comparado ao estímulo elétrico do acuponto PC6 ou ponto falso de acupuntura.

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