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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.
21

The biochemical and drug binding characteristics of two ABC transporters /

Karwatsky, Joel Michael January 2005 (has links)
No description available.
22

Toxicological Analysis of Tacrines and Verapamil on the Yellow Fever Mosquito, Aedes aegypti

Pham, Ngoc Nhu 01 July 2016 (has links)
Mosquitoes affect human health worldwide as a result of their ability to vector multiple diseases. Mosquitocide resistance is a serious public health challenge that warrants the development of improved chemical control strategies for mosquitoes. Previous studies demonstrate the mosquito blood-brain barrier (BBB) to interfere with the target-site delivery and action of anticholinesterase chemistries. The ATP-binding cassette (ABC) transporters are efflux proteins that assist in maintaining the BBB interface and serve as a first line of defense to mosquitocide exposures. To date, there are three subfamilies (ABC -B, -C, -G) of ABC transporters; however, knowledge of these chemistries interacting with mosquito ABC transporter(s) is limited. Here, I report that tacrine and bis(7)-tacrine are relative non-toxic anticholinesterases at solubility limits; however, the addition of verapamil enhances toxicity of both tacrine and bis(7)-tacrine to mosquitoes. Verapamil significantly increases the mortality of mosquitoes exposed to tacrine and bis(7)-tacrine compared to the tacrine- and bis(7)- tacrine-only treatments. Tacrine and bis(7)-tacrine reduce acetylcholinesterase activity in mosquito head preparations compared to the untreated mosquitoes; however, the addition of verapamil significantly increases the anticholinesterase activity of tacrine and bis(7)-tacrine compared to the tacrine-and bis(7)-tacrine-only treatments. Tacrine and bis(7)-tacrine increase ATPase activity in Aedes aegypti at lower concentrations compared to that of verapamil (Fig. 3). The differential increase in ATPase activity suggests that tacrine and bis(7)-tacrine are more suitable substrates for ABC transporter(s) compared to verapamil and, thus, provides putative evidence that ABC transporter(s) is a pharmacological obstacle to the delivery of these anticholinesterases to their intended target site. / Master of Science in Life Sciences
23

Influência de solventes na disposição cinética e no metabolismo enantiosseletivos do verapamil em ratos / Influence of solvents on the kinetic disposition and enantioselective metabolism of verapamil in rats

Mateus, Fabiano Henrique 20 August 2007 (has links)
O verapamil (VER) é um composto quiral comercializado como mistura racêmica dos enantiômeros (+)-(R)-VER e (-)-(S)-VER. O VER é biotransformado em norverapamil (NOR) e em outros metabólitos por vias dependentes do CYP. O tolueno e o n-hexano são solventes orgânicos que podem alterar o metabolismo de medicamentos dependente do CYP. Assim, o estudo investiga a estereosseletividade na farmacocinética do verapamil administrado a ratos na dose de 10 mg kg-1, sob forma racêmica, e do seu metabólito, norverapamil, bem como a influência do n-hexano e do tolueno na disposição cinética dos enantiômeros (+)-(R) e (-)-(S)-VER e (R)- e (S)-norverapamil em animais tratados com os solventes por inalação em câmara de exposição do tipo nose only nas concentrações de 88, 176 e 352 mg/m3 para o n-hexano e 94, 188 e 376 mg/m3 para o tolueno. Os enantiômeros do VER e do NOR foram separados na coluna de fase quiral Chiralpak® AD e analisados por LC-MS/MS (m/z = 441,3->165,5 para os enantiômeros do norverapamil e m/z 455,3->165,5 para os enantiômeros do verapamil). A análise farmacocinética foi realizada com base no modelo monocompartimental. A farmacocinética do verapamil é estereosseletiva em ratos do grupo controle não tratado com os solventes com acúmulo plasmático do eutômero (-)-(S)-VER (AUC0-? = 250,8 vs 120,4 ng mL-1 h; P<=0,05, teste de Wilcoxon). O metabólito (S)-NOR também foi acumulado no plasma dos animais do grupo controle com razão S/R relativa ao parâmetro AUC0-? de 1,5. Os parâmetros farmacocinéticos AUC0-?, Cl/F, Vd/F e t1/2 relativos aos enantiômeros (-)-S e (+)-(R)-VER e aos enantiômeros (S) e (R)-NOR não foram alterados pela exposição em câmara de exposição do tipo nose only ao n-hexano nas concentrações de 88, 176 e 352 mg/m3 e ao tolueno nas concentrações de 94, 188 e 376 mg/m3; teste de Kruskall-Wallis; P<=0,05. No entanto, a exposição ao n-hexano nas concentrações de 176 mg/m3 e 352 mg/m3 e ao tolueno nas concentrações de 94 mg/m3, 188 mg/m3 e 376 mg/m3 resultou em perda da enantiosseletividade observada para o grupo controle. / Verapamil (VER) is a chiral compound which is commercialized as a racemic mixture of the (+)-(R)-VER and (-)-(S)-VER enantiomers. VER is biotransformed into norverapamil (NOR) and other metabolites through CYP-dependent pathways. Toluene and n-hexane are organic solvents that can alter the metabolism of CYP-dependent drugs. The present study investigated the stereoselectivity in the pharmacokinetics of racemic VER administered to rats at a dose of 10 mg kg-1 and of its metabolite NOR. In addition, the influence of n-hexane and toluene on the kinetic disposition of the (+)-(R) and (-)-(S)-VER and (R)- and (S)-NOR enantiomers was analyzed in animals exposed by nose-only inhalation to n-hexane at concentrations of 88, 176 and 352 mg/m3 and to toluene at concentrations of 94, 188 and 376 mg/m3. The VER and NOR enantiomers were separated on a Chiralpak® AD chiral phase column and analyzed by LC-MS/MS (m/z = 441.3->165.5 for the NOR enantiomers and m/z 455.3->165.5 for the VER enantiomers). Pharmacokinetic analysis was performed using a monocompartmental model. The pharmacokinetics of VER was stereoselective in control rats not treated with the solvents, with plasma accumulation of the (-)-(S)-VER eutomer (AUC0-? = 250.8 vs 120.4 ng mL-1 h; P<=0.05, Wilcoxon test). The (S)-NOR metabolite was also found to accumulate in plasma of control animals, with an S/R AUC0-? ratio of 1.5. The pharmacokinetic parameters AUC0-?, Cl/F, Vd/F and t1/2 obtained for the (-)-S-VER, (+)-(R)-VER, (S)-NOR and (R)-NOR enantiomers were not altered by nose-only exposure to n-hexane at concentrations of 88, 176 and 352 mg/m3 or to toluene at concentrations of 94, 188 and 376 mg/m3 (P<=0.05), Kruskal-Wallis test). However, exposure to 176 and 352 mg/m3 n-hexane and to 94, 188 and 376 mg/m3 toluene resulted in the loss of enantioselectivity observed for the control group.
24

Verapamil diminui a expressão proteica de calpaína-1 e metaloproteinase de matriz-2 na hipertrofia cardíaca induzida por hipertensão renovascular / Verapamil decreases calpain-1 and matrix metalloproteinase-2 levels in renovascular hypertension-induced cardiac hypertrophy

Mendes, Atlante Silva 30 August 2018 (has links)
Introdução: A hipertrofia cardíaca induzida por sobrecarga hemodinâmica crônica (HC) é caracterizada por espessamento das paredes do ventrículo esquerdo e do tecido intersticial. As atividades aumentadas de calpaína-1 e metaloproteinase de matriz(MMP)-2 são observadas em diferentes modelos de hipertensão arterial e estão relacionadas com as mudanças fisiopatológicas na HC. Por outro lado, a atividade de MMP-2 parece ser modulada positivamente por ativação de calpaína-1 em diferentes modelos. O objetivo deste trabalho é analizar se a calpaína-1 contribui para o aumento da atividade de MMP-2 no coração e se esse mecanismo resulta nas mudanças crônicas cardíacas na hipertensão renovascular. Métodos: Ratos Wistar submetidos ao modelo de 2-rins-1 clipe (2R-1C)(180-200g) e seus respectivos controles (Sham) foram tratados com verapamil (VRP), um bloqueador de canais para cálcio tipo L (BCCL, 8mg/kg/bid) ou veículo durante 8 semanas. O BCCL reduz as concentrações intracelulares de cálcio, o que leva à diminuição da ativação de calpaína-1, e então à possível modulação da atividade e expressão proteica de MMP-2. Pressão arterial sistólica (PAS) dos ratos foi monitorada durante 10 semanas de hipertensão por pletismografia de cauda. O ventrículo esquerdo (VE) foi analisado por histologia e ecocardiografia para avaliação das dimensões ventriculares. A atividade de calpaína-1 e MMP-2 foi avaliada por zimografia em gel. A expessão proteica de calpaína-1 e MMP-2 foi avaliada por western blot e imunofluorescência. Os corações foram submetidos à avaliação funcional por Langendorff. Todos os protocolos foram aprovados pelo Comitê de Ética em Pesquisa Animal da Faculdade de Medicina de Ribeirão Preto (43/2017). Resultados: Após 10 semanas, a PAS teve um aumento sustentado nos animais 2R-1C e o tratamento com VRP não foi capaz de reduzí-la em nenhum tempo de hipertensão. O peso corporal não apresentou diferença significativa entre os grupos. O grupo hipertenso teve um aumento da massa cardíaca quando comparado ao sham e o tratamento com verapamil reduziu esse parâmetro. A análise da espessura do ventrículo esquerdo demonstra que o VRP é capaz de reverter a HC induzida por sobrecarga pressórica nos animais hipertensos. Os animais 2R-1C apresentaram um aumento singificativo na expressão proteica e atividade de calpaína-1 e o VRP foi capaz de diminuir esses níveis. Foi observado aumento da atividade das isoformas de MMP-2 nos ratos 2R-1C quando comparados aos controles e o VRP foi capaz de reduzir a atividade da isoforma de 64kDa. A contratilidade cardíaca intrínseca dos animais 2R-1C sugere uma disfunção cardíaca quando comparados aos controles sham, embora a fração de ejeção desses animais esteja preservada. O VRP não foi capaz de alterar esses parâmetros. Conclusão: O VRP pode contribuir para a redução da hipertrofia cardíaca por diminuir a expressão proteica de calpaína-1 e MMP-2 na hipertensão renovascular. Apoio financeiro: Capes, CNPq, FAPESP / Introduction: The chronic hemodynamic overload-induced cardiac hypertrophy (CH) is characterized by thickening of the left ventricle walls and hypertrophy of the cardiomyocytes and interstitial tissue. Increased activity of calpain-1 and matrix metalloproteinase(MMP)-2 was observed in different models of arterial hypertension models and contributes to the pathophysiologic changes shown in CH. On the other hand, MMP-2 activity is also positively modulated by activation of calpain-1 in different animal models of cardiovascular diseases. The objectives here are to analyze whether calpain-1 contributes to increase the activity of MMP-2 in the heart and whether this mechanism results in chronic cardiac changes in the renovascular hypertension. Methods: Two kidney-one clip (2K1C) hypertensive male Wistar rats (180-200g) and their respective controls (Sham) were orally treated with verapamil (VRP), a L-type calcium channels blocker (LCCB, 8mg/kg/bid), or vehicle during 8 weeks. The LCCB reduces the intracellular concentration of calcium, thus decreasing the activation of calpain-1, and then may modulate the activity of MMP-2. Systolic blood pressure (SBP) was monitored in the rats during 10 weeks of hypertension. Left ventricle (LV) was analyzed by histology and echocardiography to evaluate ventricle thickening. Calpain- 1 and MMP-2 activities were analyzed by zymography and their expression by immunofluorescence and western blot. Hearts were submitted to functional evaluation by Langendorff. All the protocols were approved by the Ethical Committee in Animal Research of Ribeirao Preto Medical School (43/2017). Results: After 10 weeks, the systolic blood pressure had sustained increase and treatment with VRP was not able to decrease it in any time of hypertension. The body weight did not present significant changes between the groups. Hypertensive group had significant increase in the ventricle/body weight ratio (VW/BW) when compared to sham and treatment with VRP decreased it. Analysis of ventricle thickening showed that VRP is able to revert CHinduced pressure overload. The 2K-1C rats showed a significant increase in the activity and expression of calpain-1 in the heart and VRP reverted it. It was also observed increased activity of MMP-2 forms in the hypertensive rats and VRP decreased the 64kDa MMP-2 activity. The 2K-1C group had cardiac dysfunction when compared to controls groups, and VRP did not alter it. The ejection fraction was not changed in 2K- 1C rats. Conclusion: VRP decreased expression and activity of calpain-1 and MMP-2 in the hearts of 2K-1C rats and then contributed to ameliorate hypertension-induced cardiac hypertrophy
25

Verapamil diminui a expressão proteica de calpaína-1 e metaloproteinase de matriz-2 na hipertrofia cardíaca induzida por hipertensão renovascular / Verapamil decreases calpain-1 and matrix metalloproteinase-2 levels in renovascular hypertension-induced cardiac hypertrophy

Atlante Silva Mendes 30 August 2018 (has links)
Introdução: A hipertrofia cardíaca induzida por sobrecarga hemodinâmica crônica (HC) é caracterizada por espessamento das paredes do ventrículo esquerdo e do tecido intersticial. As atividades aumentadas de calpaína-1 e metaloproteinase de matriz(MMP)-2 são observadas em diferentes modelos de hipertensão arterial e estão relacionadas com as mudanças fisiopatológicas na HC. Por outro lado, a atividade de MMP-2 parece ser modulada positivamente por ativação de calpaína-1 em diferentes modelos. O objetivo deste trabalho é analizar se a calpaína-1 contribui para o aumento da atividade de MMP-2 no coração e se esse mecanismo resulta nas mudanças crônicas cardíacas na hipertensão renovascular. Métodos: Ratos Wistar submetidos ao modelo de 2-rins-1 clipe (2R-1C)(180-200g) e seus respectivos controles (Sham) foram tratados com verapamil (VRP), um bloqueador de canais para cálcio tipo L (BCCL, 8mg/kg/bid) ou veículo durante 8 semanas. O BCCL reduz as concentrações intracelulares de cálcio, o que leva à diminuição da ativação de calpaína-1, e então à possível modulação da atividade e expressão proteica de MMP-2. Pressão arterial sistólica (PAS) dos ratos foi monitorada durante 10 semanas de hipertensão por pletismografia de cauda. O ventrículo esquerdo (VE) foi analisado por histologia e ecocardiografia para avaliação das dimensões ventriculares. A atividade de calpaína-1 e MMP-2 foi avaliada por zimografia em gel. A expessão proteica de calpaína-1 e MMP-2 foi avaliada por western blot e imunofluorescência. Os corações foram submetidos à avaliação funcional por Langendorff. Todos os protocolos foram aprovados pelo Comitê de Ética em Pesquisa Animal da Faculdade de Medicina de Ribeirão Preto (43/2017). Resultados: Após 10 semanas, a PAS teve um aumento sustentado nos animais 2R-1C e o tratamento com VRP não foi capaz de reduzí-la em nenhum tempo de hipertensão. O peso corporal não apresentou diferença significativa entre os grupos. O grupo hipertenso teve um aumento da massa cardíaca quando comparado ao sham e o tratamento com verapamil reduziu esse parâmetro. A análise da espessura do ventrículo esquerdo demonstra que o VRP é capaz de reverter a HC induzida por sobrecarga pressórica nos animais hipertensos. Os animais 2R-1C apresentaram um aumento singificativo na expressão proteica e atividade de calpaína-1 e o VRP foi capaz de diminuir esses níveis. Foi observado aumento da atividade das isoformas de MMP-2 nos ratos 2R-1C quando comparados aos controles e o VRP foi capaz de reduzir a atividade da isoforma de 64kDa. A contratilidade cardíaca intrínseca dos animais 2R-1C sugere uma disfunção cardíaca quando comparados aos controles sham, embora a fração de ejeção desses animais esteja preservada. O VRP não foi capaz de alterar esses parâmetros. Conclusão: O VRP pode contribuir para a redução da hipertrofia cardíaca por diminuir a expressão proteica de calpaína-1 e MMP-2 na hipertensão renovascular. Apoio financeiro: Capes, CNPq, FAPESP / Introduction: The chronic hemodynamic overload-induced cardiac hypertrophy (CH) is characterized by thickening of the left ventricle walls and hypertrophy of the cardiomyocytes and interstitial tissue. Increased activity of calpain-1 and matrix metalloproteinase(MMP)-2 was observed in different models of arterial hypertension models and contributes to the pathophysiologic changes shown in CH. On the other hand, MMP-2 activity is also positively modulated by activation of calpain-1 in different animal models of cardiovascular diseases. The objectives here are to analyze whether calpain-1 contributes to increase the activity of MMP-2 in the heart and whether this mechanism results in chronic cardiac changes in the renovascular hypertension. Methods: Two kidney-one clip (2K1C) hypertensive male Wistar rats (180-200g) and their respective controls (Sham) were orally treated with verapamil (VRP), a L-type calcium channels blocker (LCCB, 8mg/kg/bid), or vehicle during 8 weeks. The LCCB reduces the intracellular concentration of calcium, thus decreasing the activation of calpain-1, and then may modulate the activity of MMP-2. Systolic blood pressure (SBP) was monitored in the rats during 10 weeks of hypertension. Left ventricle (LV) was analyzed by histology and echocardiography to evaluate ventricle thickening. Calpain- 1 and MMP-2 activities were analyzed by zymography and their expression by immunofluorescence and western blot. Hearts were submitted to functional evaluation by Langendorff. All the protocols were approved by the Ethical Committee in Animal Research of Ribeirao Preto Medical School (43/2017). Results: After 10 weeks, the systolic blood pressure had sustained increase and treatment with VRP was not able to decrease it in any time of hypertension. The body weight did not present significant changes between the groups. Hypertensive group had significant increase in the ventricle/body weight ratio (VW/BW) when compared to sham and treatment with VRP decreased it. Analysis of ventricle thickening showed that VRP is able to revert CHinduced pressure overload. The 2K-1C rats showed a significant increase in the activity and expression of calpain-1 in the heart and VRP reverted it. It was also observed increased activity of MMP-2 forms in the hypertensive rats and VRP decreased the 64kDa MMP-2 activity. The 2K-1C group had cardiac dysfunction when compared to controls groups, and VRP did not alter it. The ejection fraction was not changed in 2K- 1C rats. Conclusion: VRP decreased expression and activity of calpain-1 and MMP-2 in the hearts of 2K-1C rats and then contributed to ameliorate hypertension-induced cardiac hypertrophy
26

Influência de solventes na disposição cinética e no metabolismo enantiosseletivos do verapamil em ratos / Influence of solvents on the kinetic disposition and enantioselective metabolism of verapamil in rats

Fabiano Henrique Mateus 20 August 2007 (has links)
O verapamil (VER) é um composto quiral comercializado como mistura racêmica dos enantiômeros (+)-(R)-VER e (-)-(S)-VER. O VER é biotransformado em norverapamil (NOR) e em outros metabólitos por vias dependentes do CYP. O tolueno e o n-hexano são solventes orgânicos que podem alterar o metabolismo de medicamentos dependente do CYP. Assim, o estudo investiga a estereosseletividade na farmacocinética do verapamil administrado a ratos na dose de 10 mg kg-1, sob forma racêmica, e do seu metabólito, norverapamil, bem como a influência do n-hexano e do tolueno na disposição cinética dos enantiômeros (+)-(R) e (-)-(S)-VER e (R)- e (S)-norverapamil em animais tratados com os solventes por inalação em câmara de exposição do tipo nose only nas concentrações de 88, 176 e 352 mg/m3 para o n-hexano e 94, 188 e 376 mg/m3 para o tolueno. Os enantiômeros do VER e do NOR foram separados na coluna de fase quiral Chiralpak® AD e analisados por LC-MS/MS (m/z = 441,3->165,5 para os enantiômeros do norverapamil e m/z 455,3->165,5 para os enantiômeros do verapamil). A análise farmacocinética foi realizada com base no modelo monocompartimental. A farmacocinética do verapamil é estereosseletiva em ratos do grupo controle não tratado com os solventes com acúmulo plasmático do eutômero (-)-(S)-VER (AUC0-? = 250,8 vs 120,4 ng mL-1 h; P<=0,05, teste de Wilcoxon). O metabólito (S)-NOR também foi acumulado no plasma dos animais do grupo controle com razão S/R relativa ao parâmetro AUC0-? de 1,5. Os parâmetros farmacocinéticos AUC0-?, Cl/F, Vd/F e t1/2 relativos aos enantiômeros (-)-S e (+)-(R)-VER e aos enantiômeros (S) e (R)-NOR não foram alterados pela exposição em câmara de exposição do tipo nose only ao n-hexano nas concentrações de 88, 176 e 352 mg/m3 e ao tolueno nas concentrações de 94, 188 e 376 mg/m3; teste de Kruskall-Wallis; P<=0,05. No entanto, a exposição ao n-hexano nas concentrações de 176 mg/m3 e 352 mg/m3 e ao tolueno nas concentrações de 94 mg/m3, 188 mg/m3 e 376 mg/m3 resultou em perda da enantiosseletividade observada para o grupo controle. / Verapamil (VER) is a chiral compound which is commercialized as a racemic mixture of the (+)-(R)-VER and (-)-(S)-VER enantiomers. VER is biotransformed into norverapamil (NOR) and other metabolites through CYP-dependent pathways. Toluene and n-hexane are organic solvents that can alter the metabolism of CYP-dependent drugs. The present study investigated the stereoselectivity in the pharmacokinetics of racemic VER administered to rats at a dose of 10 mg kg-1 and of its metabolite NOR. In addition, the influence of n-hexane and toluene on the kinetic disposition of the (+)-(R) and (-)-(S)-VER and (R)- and (S)-NOR enantiomers was analyzed in animals exposed by nose-only inhalation to n-hexane at concentrations of 88, 176 and 352 mg/m3 and to toluene at concentrations of 94, 188 and 376 mg/m3. The VER and NOR enantiomers were separated on a Chiralpak® AD chiral phase column and analyzed by LC-MS/MS (m/z = 441.3->165.5 for the NOR enantiomers and m/z 455.3->165.5 for the VER enantiomers). Pharmacokinetic analysis was performed using a monocompartmental model. The pharmacokinetics of VER was stereoselective in control rats not treated with the solvents, with plasma accumulation of the (-)-(S)-VER eutomer (AUC0-? = 250.8 vs 120.4 ng mL-1 h; P<=0.05, Wilcoxon test). The (S)-NOR metabolite was also found to accumulate in plasma of control animals, with an S/R AUC0-? ratio of 1.5. The pharmacokinetic parameters AUC0-?, Cl/F, Vd/F and t1/2 obtained for the (-)-S-VER, (+)-(R)-VER, (S)-NOR and (R)-NOR enantiomers were not altered by nose-only exposure to n-hexane at concentrations of 88, 176 and 352 mg/m3 or to toluene at concentrations of 94, 188 and 376 mg/m3 (P<=0.05), Kruskal-Wallis test). However, exposure to 176 and 352 mg/m3 n-hexane and to 94, 188 and 376 mg/m3 toluene resulted in the loss of enantioselectivity observed for the control group.
27

Characterisation of Grape and Grape pomace Polyphenolics : their Absorption and Metabolism and Potential Effects on Hypertension in a SHR Rat Model / Caractérisation d’Antioxydants Phénoliques de Raisins et de Marcs : leur Absorption, Métabolisme et Effets Potentiels sur l’Hypertension dans un Modèle de Rats SHR (Spontanément Hypertendus)

Ky, Isabelle 13 December 2013 (has links)
Cette étude examine les effets bénéfiques des marcs de raisins obtenus après vinification de différents cépages caractéristiques de la Vallée du Rhône, de leurs compositions phénoliques à leurs effets in vivo. Les raisins et leurs marcs respectifs des cépages Grenache (provenant de deux endroits différents [GRE1] et [GRE2]), Syrah (provenant de deux endroits différents [SYR1] et [SYR2]), Carignan (CAR), Mourvèdre (MOU), Counoise (COU) et Alicante (ALI) ont été étudiés. La comparaison des extraits de raisins et de leurs marcs respectifs montre que les marcs représentent une source importante d’antioxydants phénoliques malgré le processus de vinification. Les pépins et pellicules de marcs renferment des quantités appréciables de flavan-3-ols et anthocyanes. La distribution qualitative et quantitative des polyphenols dans les marcs de raisin présentent des différences significatives au travers des variétés et millésimes allant de 15% à 70% de polyphénols extraits. Les pépins de Grenache (GRE1), Syrah (SYR1) et les pellicules de Syrah (SYR1), Carignan et Alicante sont les fractions les plus intéressantes dues a la présence d’importantes quantités de flavan-3-ols (monomères, dimères et trimère) jusqu’à 8.7 mg/g MS et d’anthocyanes (glycosylées, acétylées et coumaroylées jusqu’à 17.40 mg/g MS, 1.57 mg/g MS et 2.38 mg/g MS respectivement). L’analyse des extraits aqueux (EAQ) et hydro-alcoolique 70% (EA70) indique que les pépins de Carignan et Syrah (SYR1) et les pellicules de Carignan et d’Alicante contiennent les plus fort taux en composés phénoliques et activités antioxydantes. L’efficacité in vivo sur l’hypertension de certains extraits a été évaluée utilisant un modèle de rat SHR. Les résultats des expériences in vivo démontrent que certains extraits administrés seuls ou en association avec le vérapamil possèdent un effet anti-hypertenseur. Cette capacité a été mise en évidence une fois que les extraits de pépins de marcs de GRE1 (EA70) et SYR1 (EA70) et de pellicules de marcs d’ALI (EA70) ont été administrés seuls ou lorsque les extraits de pépins de marcs GRE1 (EA70) et SYR1 (EAQ) et les pellicules de marcs d’ALI (EA70) et SYR2 (EAQ) ont été administrés en association avec le vérapamil. Cette étude met en évidence la biodisponibilité des extraits de pépins et de pellicules de marcs des rats SHR incluant à la fois le métabolisme de phase II et de la microflore intestinale. Les extraits de marcs administrés seuls et en association au vérapamil sont absorbés en tant que métabolites de phase II dérivant du métabolisme des monomères de flavan-3-ols. La détection de métabolites microbiens dérivés de flavan-3-ols, d’hydroxyphényl-γ-valérolactones sous leurs formes glucuronidés et sulfatés confirme l'absorption des métabolites dérivés des flavan-3-ols monomères et polymères et des conjugaisons supplémentaires dans le foie. De nombreux métabolites issus de la dégradation microbienne des hydroxyvalerolactones ont également été détectés. L’excrétion urinaire de ces métabolites représente une plus grande proportion de polyphénols ingérés comparé à ceux issus de métabolisme de phase II des monomères de flavan-3-ols, indiquant un rôle important des bactéries intestinales dans le métabolisme des molécules hautement polymérisées. Ces métabolites peuvent avoir exercé leurs effets biologiques lors de leur passage dans la circulation sanguine. Cette étude constitue une première étape de valorisation de marcs de raisins après vinification, en tant qu’activateur de vérapamil, un médicament couramment utilisé contre l’hypertension. Des quantités suffisantes de composés phénoliques subsistent dans les marcs, en particulier en terme de flavan-3-ols et d’anthocyanes, pour exercer des effets antihypertenseurs. En effet, selon le type et la composition des extraits, il est possible de moduler les effets antihypertenseurs en amplifiant ou en diminuant l’absorption des polyphénols et/ou du vérapamil. / This study investigated the beneficial potential effects of grape pomaces obtained after winemaking of different Mediterranean grape varieties from crude materials to their in vivo effectiveness. Grapes and their respective grape pomaces from six different V. vinifera L. cultivar were studied namely Grenache (from two different locations [GRE1 and GRE2]), Syrah (from two different locations [SYR1 and SYR2]), Carignan (CAR), Mourvèdre (MOU), Counoise (COU) and Alicante (ALI) grape varieties from the Rhône Valley. The comparison of several wine industry by-products with their respective grapes provided evidence that pomace remaining at the end of the winemaking process can be very rich sources of antioxidants. The quantitative and qualitative distribution of polyphenols by HPLC-PDA-Fluo-MS in grape pomaces showed significant differences through varieties and vintages varying from 15% to 70% of polyphenols extracted. Seeds from Grenache (GRE1), Syrah (SYR1) and skins from Syrah (SYR1), Carignan and Alicante were of particular interest because of their higher polyphenol contents in terms of flavan-3-ols (monomers, dimers and trimers) up to 8.7 mg/g DW and anthocyanins (glycosides, acetylated and coumaroylated derivatives up to 17.40, 1.57 and 2.38 mg/g DW, respectively). The investigation of aqueous and hydro-alcoholic 70% extracts of seeds from Carignan and Syrah (SYR1) and skins from Carignan and Alicante was carried out as they contained high levels of total phenols and antioxidant activity. Several extracts, were tested in order to evaluate their in vivo biological effects on hypertension using a spontaneously hypertensive rat (SHR) model. A series of different grape pomace extracts were tested in association with verapamil. All in vivo experiments demonstrated that some grape pomace extracts administrated with or without co-ingestion with verapamil possessed an anti-hypertensive activity. This was evident with GRE1 (EA70) seed pomace extract, SYR1 (EA70) seed pomace extract, ALI (EA70) skin pomace extract administrated alone and with GRE1 (EA70) seed pomace extract, SYR1 (EAQ) seed pomace extract, ALI (EA70) skin pomace extract and SYR2 (EAQ) skin pomace extract administrated in association with verapamil. Grape pomace extracts with or without co-ingestion with verapamil were absorb as phase II metabolites mainly including glucuronide, O-methyl glucuronide, sulfate, and O-methyl sulfate derivatives of (epi)catechin which arise from the metabolism of monomeric flavan-3-ols. The detection by HPLC-PDA-Fluo-MSn and GC-MS of microbial-derived metabolites of flavan-3-ols, hydroxyphenyl-γ-valerolactones in their glucuronide and sulfate forms confirmed the absorption of metabolites derived from both monomeric and polymeric flavan-3-ols from grape pomace extracts and subsequent post-absorption conjugation. Numerous metabolites derived from further microbial degradation of hydroxyvalerolactones were also detected. The urinary excretion of these metabolites accounted for a larger proportion of the total polyphenol ingested than phase II metabolites of monomeric flavan-3-ols, indicating the important role of intestinal bacteria in the metabolism of polymerized procyanidins. All these metabolites may have exerted biological effects during the period in which they circulated in the bloodstream. This study constitutes the first step of assessing grape pomace as an enhancer of the verapamil, an anti-hypertensive drug. Substantial levels of polyphenols, especially flavan-3-ols, procyanidins and anthocyanins, remain in pomace after the winemaking process in quantities sufficient to exert anti-hypertensive effects. In addition, according to the extract used and its composition, it is feasible to modulate anti-hypertensive effects by amplifying or decreasing polyphenols and/or verapamil absorption.
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Influência do verapamil na farmacocinética e na perfusão cerebral da oxcarbazepina e dos enantiômeros do metabólito 10-hidroxicarbazepina em voluntários sadios / Influence of verapamil on the pharmacokinetics and cerebral perfusion of oxcarbazepine and the enantiomers of its metabolite 10- hydroxycarbazepine in healthy volunteers

Antunes, Natalicia de Jesus 25 November 2014 (has links)
A oxcarbazepina (OXC) é indicada como terapia adjuvante ou monoterapia no tratamento de crises epilépticas parciais ou crises tônico-clônicas generalizadas em adultos e crianças. A OXC sofre rápida eliminação pré-sistêmica com formação do metabólito ativo 10-hidroxicarbazepina (MHD), o qual possui como enantiômeros o R-(-)- e o S-(+)-MHD. A OXC e o MHD são substratos da glicoproteína-P (P-gp), que pode ser inibida pelo verapamil. O presente estudo avalia a influência do verapamil na farmacocinética e perfusão cerebral da OXC e dos enantiômeros do MHD em voluntários sadios. Os voluntários sadios (n=12) receberam em uma ocasião doses de 300 mg/12h de OXC e em outra ocasião doses de 300 mg/12h de OXC associadas com 80 mg/8h de verapamil. As amostras de sangue foram coletadas no estado de equilíbrio durante 12 horas e a avaliação da perfusão cerebral realizada utilizando a tomografia computadorizada por emissão de fóton único (SPECT) antes do início do tratamento e nos tempos 4, 6 ou 12h após a administração da OXC. As concentrações plasmáticas total e livre da OXC e dos enantiômeros do MHD foram avaliadas por LC-MS/MS. A análise farmacocinética não compartimental foi realizada com o programa WinNonlin e a farmacocinética populacional foi desenvolvida utilizando a modelagem não-linear de efeitos mistos com o programa NONMEM. Os limites de quantificação obtidos foram de 12,5 ng OXC/mL de plasma e 31,25 ng de cada enantiômero MHD/mL de plasma para a análise da concentração total, enquanto foi de 4,0 ng de OXC/mL de plasma e de 20,0 ng de cada enantiômero do MHD/mL de plasma para a determinação da concentração livre. Os coeficientes de variação obtidos nos estudos de precisão e a porcentagem de inexatidão inter e intra-ensaios foram inferiores a 15%, assegurando a reprodutibilidade e repetibilidade dos resultados. A análise farmacocinética não compartimental da OXC em monoterapia resultou nos seguintes parâmetros: concentração plasmática máxima (Cmax) de 1,35 ?g/mL como valor total e 0,32 ?g/mL como concentração livre em 1,0 h, área sob a curva concentração plasmática versus tempo (AUC0-12) de 3,98 ?g.h/mL e meia-vida de eliminação de 2,45 h, volume de distribuição aparente (Vss/F) de 352,17 L e clearance aparente (CLss/F) de 75,58 L/h. A disposição cinética do MHD é enantiosseletiva, com observação de maior proporção para o enantiômero S-(+)-MHD em relação ao R-(-)-MHD (razão AUC0-12 S-(+)/R-(-) de 4,26). A fração livre avaliada no tmax da OXC foi 0,26 para a OXC, 0,42 para o R-(-)-MHD e 0,38 para o S- (+)-MHD, mostrando enantiosseletividade na ligação às proteínas plasmáticas do MHD. O tratamento com o verapamil reduziu o tempo médio de residência (MRT) (4,71 vs 3,83 h) e Cmax como concentração livre (0,32 vs 0,53 ?g/mL) da OXC e aumentou os valores para ambos os enantiômeros do MHD de Cmax como valor total (2,60 vs 3,27 ?g/mL para o R-(-)- e 11,05 vs 11,94 ?g/mL para o S-(+)-MHD), Cmax como concentração livre (3,11 vs 4,14 ?g/mL para o S-(+)-MHD), Cmédia (2,11 vs 2,42 ?g/mL para o R-(-)- e 8,10 vs 9,07 ?g/mL para o S-(+)-MHD) e AUC0-12 (25,36 vs 29,06 ?g.h/mL para o R-(-)- e 97,19 vs 111,37 ?g.h/mL para o S-(+)-MHD). A ii farmacocinética populacional da OXC foi melhor descrita por modelo de dois compartimentos com eliminação de primeira ordem e com um conjunto de três compartimentos de trânsito para descrever o perfil de absorção da OXC. A disposição de ambos os enantiômeros do MHD foi caracterizada por modelo de um compartimento. Os valores de CLss/F estimados na monoterapia foram de 84,9 L/h para a OXC e de 2,0 L/h para ambos enantiômeros do MHD, enquanto os valores de Vss/F foram de 587 L para a OXC, 23,6 L para o R-(-)-MHD e 31,7 L para o S-(+)- MHD. Concluindo, a associação do verapamil aumentou a biodisponibilidade da OXC em 12% (farmacocinética populacional) e aumentou os valores de AUC de ambos os enantiômeros do metabólito MHD (farmacocinética não compartimental), o que está provavelmente relacionado com a inibição da P-gp no trato intestinal. A associação do verapamil aumentou as concentrações cerebrais preditas de ambos os enantiômeros do MHD em maior extensão do que aquelas observadas no plasma. As mudanças no fluxo sanguíneo cerebral (SPECTs realizados 6h após a administração da OXC) associadas à coadministração de verapamil provavelmente foram causadas pelo aumento dos níveis cerebrais de ambos os enantiômeros do MHD. A confirmação dessa observação requer um braço experimental adicional com SPECTs realizados também após a administração do verapamil em monoterapia. / Oxcarbazepine (OXC) is indicated as adjunctive therapy or monotherapy for the treatment of partial or generalized tonic-clonic seizures in adults and children. OXC undergoes rapid pre-systemic reduction with formation of the active metabolite 10- hydroxycarbazepine (MHD), which has the enantiomers R-(-)- and S-(+)-MHD. OXC and MHD are substrates of P-glycoprotein (P-gp), which can be inhibited by verapamil. The present study evaluates the influence of verapamil on the pharmacokinetics and cerebral perfusion of OXC and the MHD enantiomers in healthy volunteers. The healthy volunteers (n=12) received on one occasion doses of 300 mg/12h OXC and on another occasion they received doses of 300 mg/12h OXC associated with 80 mg/8h of verapamil. Blood samples were collected at steady state for 12 hours and the assessment of cerebral perfusion was performed using a single-photon emission computed tomography (SPECT) before the beginning of treatment and at times 4, 6 or 12 hours after OXC administration. The total and free plasma concentrations of OXC and MHD enantiomers were assessed by LC-MS/MS. The non-compartmental pharmacokinetics analysis was performed using the WinNonlin program, and population pharmacokinetics was developed using nonlinear mixed effects modelling with NONMEM.The limits of quantification obtained were 12.5 ng/mL plasma for OXC and 31.25 ng of each MHD enantiomer/mL plasma for total concentration analysis, while it was 4.0 ng OXC/mL plasma and 20.0 ng of each MHD enantiomer/mL plasma for the free concentration determination. The coefficients of variation obtained in studies of accuracy and the percentage of inaccuracy inter and intra-assay were less than 15%, ensuring the result reproducibility and repeatability. The non-compartmental pharmacokinetic analysis of OXC in monotherapy treatment, resulted in the following parameters: maximum plasma concentration (Cmax) of 1.35 ?g/mL as total concentration and 0.32 mg/mL as free concentration in 1.0 h, area under the plasma concentration vs time curve (AUC0-12) was 3.98 ?g.h/mL, half-life of 2.45 h, apparent volume of distribution (Vss/F) of 352.17 L and the apparent clearance (CLSS/F) of 75.58 L/h. The MHD kinetic disposition is enantioselective, with observation of a greater proportion of the S-(+)-MHD enantiomer compared to R-(-)-MHD (ratio AUC0-12 S-(+)/R-(-) of 4.26). The free fraction measured in the tmax of OXC was 0.26 for OXC, 0.42 for R-(-)-MHD and 0.38 for S-(+)-MHD, showing enantioselectivity in the plasma protein binding of MHD. Verapamil treatment reduced the mean residence time (MRT) (4.71 vs 3.83 h) and Cmax (0.26 vs 0.31 ?g/mL) as free concentration for OXC and increased the both MHD enantiomers values of Cmax (2.60 vs 3.27 ?g/mL for R-(-)- and 11.94 vs 11.05 ?g/mL for S-(+)-MHD) as total concentration, Cmax (3.11 vs 4,14 ?g/mL for S- (+)-MHD) as free concentration, Cavg (2.11 vs 2.42 ?g/mL for R-(-)- and 8.10 vs 9.07 ?g/mL for S-(+)-MHD) and AUC0-12 (25.36 vs 29.06 ?g.h/mL for R-(-)- and 97.19 vs 111.37 ?g.h/mL for S-(+)-MHD). The population pharmacokinetics of oxcarbazepine was best described by a two-compartment model with first-order elimination and a iv set of three transit compartments to describe the absorption profile of the parent compound. The disposition of both MHD enantiomers was characterised by onecompartment model. The CLss/F estimates in monotherapy were 84.9 L/h for OXC and 2.0 L/h for both MHD enantiomers, whereas the values of Vss/F were 587 L for OXC, 23.6 L for R-(-)-MHD and 31.7 L for S-(+)-MHD. In conclusion, verapamil coadministration increased the OXC bioavailability in 12% (population pharmacokinetics) and increased the AUC of both metabolite MHD enantiomers (non-compartmental pharmacokinetics), which is probably related to the inhibition of P-gp in the intestinal tract. Verapamil co-administration increased the predicted brain concentrations of both MHD enantiomers in a greater extent than those observed in plasma. Changes in cerebral blood flow (SPECTs performed 6h after administration of OXC) associated with co-administration of verapamil were probably caused by an increase in brain levels of both MHD enantiomers. Confirmation of this observation requires additional experimental arm with SPECTs also performed after administration of verapamil in monotherapy.
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Funkční tenké vrstvy pro aplikace využívající pokročilé oxidační procesy / Functional thin films for applications using advanced oxidation processes

ŠRAM, Vlastimil January 2013 (has links)
This diploma thesis aims to optimalization the process of magnetron sputtering and creating of thin layers for use in advanced oxidation processes. During the work was created range of TiOx layers. For this process was used physical method of sputtering called PVD. The photocatalytic activity of the deposited films was tested by degradation of organic dyes Acid Orange 7. Furthermore, the layer was analyzed on surface morphology (SEM) and the layer thickness (profilometry). Study of created layers was focused on the link between the characteristics of each layer, deposition parameters and photocatalysis properties. Based on these results, the layers were applied in a system using AOP for the decomposition of organic substances. The first chapter is devoted to a summary of existing knowledge of photocatalysis and its principles. Another chapter is devoted to the theory and methods of applying thin layers and summary of knowledge of the low-pressure discharges. In the exprimental section there are described various components of the apparatus. Furthermore, the experimental part of the work focuses on the analysis of the optimization process of applying thin layers on titanium oxide. The last chapter of the thesis contains the results of the experiments on the basis of is designed another research progress of this issue.
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Efeitos da administração crônica da digoxina e do verapamil sobre o desempenho físico e a estrutura e função cardíaca em ratos submetidos ao treinamento físico intervalado

Neves, Claodete Hasselstrom 06 March 2015 (has links)
Submitted by Valquíria Barbieri (kikibarbi@hotmail.com) on 2018-04-17T19:55:14Z No. of bitstreams: 1 DISS_2015_Claodete Hasselstrom Neves.pdf: 1544628 bytes, checksum: c8448adc35211604eee744606435547c (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2018-04-27T17:11:37Z (GMT) No. of bitstreams: 1 DISS_2015_Claodete Hasselstrom Neves.pdf: 1544628 bytes, checksum: c8448adc35211604eee744606435547c (MD5) / Made available in DSpace on 2018-04-27T17:11:37Z (GMT). No. of bitstreams: 1 DISS_2015_Claodete Hasselstrom Neves.pdf: 1544628 bytes, checksum: c8448adc35211604eee744606435547c (MD5) Previous issue date: 2015-03-06 / O objetivo deste estudo foi investigar os efeitos da administração crônica de digoxina e do verapamil durante treinamento físico intervalado de alta intensidade (TFI) sobre o desempenho físico, capacidade funcional e morfologia cardíaca de ratos. Para tanto, 48 ratos Wistar, com 60 dias de idade, foram aleatoriamente distribuídos em 6 grupos(N=8/grupo): controle, não treinado (C), treinado, sem administração de droga (T), digoxina sem treinamento (DIGO), verapamil sem treinamento (VERA), treinado, com administração de digoxina (TDIGO) e treinado, com administração de verapamil (TVERA). A digoxina e o verapamil foram administrados via gavagem, na dose de 30μg/kg/dia e 5,0 mg/kg/dia respectivamente, durante todo o período experimental. Os grupos T, TDIGO e TVERA foram submetidos a um programa de TFI em esteira rolante durante 60 dias. Foi aplicado o teste de esforço progressivo máximo (TEM) e determinada a concentração sérica de lactato (LAC) sanguíneo. O TFI consistiu de sessões de corrida em esteira rolante 1 h/dia, 5 dias/semana por 60 dias. A intensidade de treino foi 80% da velocidade máxima (Vmáx) atingida no teste de esforço antes do TFI por 8 min e 20% da Vmáx por 2 min. A função cardíaca foi avaliada por ecocardiograma. Foi coletado o músculo esquelético, o músculo cardíaco e a gordura corporal total (GOR) para os dados anatômicos, o ventrículo esquerdo (VE) para análise histológica e o sangue para a análise bioquímica. A comparação entre os grupos foi realizada por meio da análise de variância (ANOVA) e Kruskal Wallis para o esquema de dois fatores independentes, complementada com o teste de Bonferroni, Tukey ou Dunn. O índice de significância considerado foi de 5%. A relação VE/peso corporal final (PCF), o diâmetro diastólico do VE (DDVE) e diâmetro sistólico do VE (DSVE) foram maiores no grupo TDIGO do que o grupo T e DIGO. Os parâmetros do TEM foram maiores e a concentração de LAC foi menor em ratos treinados em relação aos não treinados. A relação GOR/PCF foi menor no TDIGO e TVERA em relação ao DIGO e VERA, respectivamente. A relação VE/PCF foi maior no TVERA em relação ao VERA. O diâmetro interno do VE (DIVE) do grupo T, TDIGO e TVERA foram maiores em relação ao C, o TDIGO teve aumento em relação ao DIGO. O colesterol total e o LDL foram maiores no TDIGO comparado ao DIGO. A área do cardiomiócito foi maior nos grupos VERA e T comparados ao grupo C. Conclusão: O Treinamento intervalado promoveu hipertrofia cardíaca do tipo excêntrica. Entretanto, a administração concomitante de digoxina ou de verapamil não afetaram a morfologia cardíaca, a função cardíaca e o desempenho físico em ratos submetidos ao treinamento. / The aim of this study was to investigate the effects of chronic administration of cardiotonic (digoxin) and the calcium channel blocker (verapamil) during high-intensity interval exercise training (IET) on physical performance, functional capacity and cardiac morphology of rats. For this study, 48 Wistar rats, 60 days old, were randomly distributed into 6 groups (N = 8 / group): control, untrained (C), trained without drug administration (T), digoxin untrained (DIGO), verapamil without training (VERA), trained with digoxin administration (TDIGO) and trained with verapamil administration (TVERA). Digoxin and verapamil were administered by gavage at a dose of 30μg/kg/day and 5.0 mg.kg-1, respectively, throughout the experimental period. The groups T, TDIGO and TVERA underwent a IET program on a treadmill for 60 days. The progressive maximal exercise test was applied (TPM) and determined the serum concentration of lactate (LAC) blood. The IET consisted of sessions running on a treadmill 1 h/day, 5 days/week for 60 days. The training intensity was 80% of the maximum velocity (Vmax) achieved in the stress test before the TAI for 8 min and 20% of Vmax for 2 min. Cardiac function was assessed by echocardiography. Was collected skeletal muscle, cardiac muscle and total body fat (TBF) for anatomical data, the left ventricle (LV) for histological analysis and blood for biochemical analysis. The comparison between groups was performed using analysis of variance (ANOVA) or Kruskal Wallis for the two independent factors, complemented by the Bonferroni test, Tukey or Dunn. The significance level considered was 5%. The ratio VE final body weight (FBW), LV diastolic diameter (LVDD) and LV systolic diameter (LVSD) were higher in TDIGO group than the group T and DIGO. The parameters MET were higher and the concentration of LAC was lower in rats training in relation to the untrained. The relationship GOR/FBW was lower in TDIGO and TVERA compared to DIGO and VERA respectively. The ratio VE/FBW was higher in TVERA compared to VERA. The of the LV inside diameter (LVID) T group, TDIGO and TVERA were higher compared to C, TDIGO had increased compared to DIGO. Total cholesterol and LDL were higher in TDIGO compared to DIGO. The area of cardiomyocytes was higher in VERA and T compared to group C. Conclusion: TAI induced cardiac hypertrophy of the eccentric type. However, concomitant administration of digoxin or verapamil did not affect the cardiac morphology, cardiac function and physical performance in rats submitted to training.

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