by Mui Kin Tung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 97-113). / Chapter CHAPTER 1: --- INTRODUCTION --- p.1 / Chapter CHAPTER 2: --- LITERATURE REVIEW --- p.5 / Chapter 2.1 --- ION TRANSPORT SYSTEMS IN HUMAN ERYTHROCYTES --- p.6 / Chapter 2.1.1 --- "Sodium Pump (Na+,K+-ATPase)" --- p.6 / Chapter 2.1.2 --- Passive Sodium Transport Systems --- p.9 / Chapter 2.1.2.1 --- Sodium-potassium-chloride cotransport system --- p.9 / Chapter 2.1.2.2 --- Sodium-lithium Countertransport --- p.13 / Chapter 2.1.3 --- Ouabain- and Frusemide-Resistant Passive Effluxes --- p.17 / Chapter 2.2 --- ERYTHROCYTE SODIUM TRANSPORT SYSTEMS IN ESSENTIAL HYPERTENSION --- p.17 / Chapter 2.2.1 --- "Sodium Pump (Na+, K+-ATPase) in Essential Hypertension" --- p.18 / Chapter 2.2.2 --- Sodium-Potassium-Chloride Cotransport in Essential Hypertension --- p.20 / Chapter 2.2.3 --- Sodium-Lithium Countertransport in Essential Hypertension --- p.23 / Chapter 2.2.4 --- Passive Ion Fluxes in Essential Hypertension --- p.26 / Chapter 2.2.5 --- Intracellular Sodium Concentration in Essential Hypertension --- p.26 / Chapter 2.3 --- ERYTHROCYTE SODIUM TRANSPORT SYSTEMS IN DIABETES MELLITUS --- p.27 / Chapter CHAPTER 3: --- MATERIALS & METHODS --- p.29 / Chapter 3.1 --- MATERIALS --- p.30 / Chapter 3.1.1 --- Choline Wash Solution (CWS) --- p.30 / Chapter 3.1.2 --- Lithium Loading Solution --- p.31 / Chapter 3.1.3 --- Choline Wash Solution with Ouabain (CWS-O) --- p.31 / Chapter 3.1.4 --- Sodium Containing Medium (SCM) --- p.31 / Chapter 3.1.5 --- Sodium Free Medium (SFM) --- p.31 / Chapter 3.1.6 --- Sodium Free Medium with Bumetanide (SFM-B) --- p.32 / Chapter 3.1.7 --- Preservation Solution --- p.32 / Chapter 3.2 --- STUDY POPULATION --- p.32 / Chapter 3.2.1 --- Control Subjects --- p.35 / Chapter 3.2.2 --- Patients with Essential Hypertension --- p.35 / Chapter 3.2.3 --- Diabetic Patients --- p.35 / Chapter 3.3 --- DETERMINATION OF ERYTHROCYTE INTRACELLULAR SODIUM AND POTASSIUM CONCENTRATIONS (Naic/Kic --- p.36 / Chapter 3.3.1 --- Preparation of Erythrocytes --- p.36 / Chapter 3.3.2 --- Preparation of Haemolysates --- p.38 / Chapter 3.3.3 --- Determination of Sodium and Potassium Concentrations in Haemolysates --- p.38 / Chapter 3.3.4 --- Determination of Haemoglobin Concentration in Haemolysates --- p.38 / Chapter 3.3.5 --- Evaluation of Erythrocyte Intracellular Sodium and Potassium Concentrations --- p.39 / Chapter 3.4 --- DETERMINATION OF ERYTHROCYTE PASSIVE POTASSIUM EFFLUX --- p.39 / Chapter 3.4.1 --- Determination of Potassium Concentrations in Supernatant --- p.40 / Chapter 3.4.2 --- Evaluation of Passive Potassium Efflux --- p.40 / Chapter 3.5 --- DETERMINATION OF ERYTHROCYTE SODIUM-LITHIUM COUNTERTRANSPORT (SLC) AND LITHIUM-POTASSIUM COTRANSPORT (LPC) --- p.41 / Chapter 3.5.1 --- Lithium Loading --- p.42 / Chapter 3.5.2 --- Determination of Haematocrit --- p.42 / Chapter 3.5.3 --- Preparation of Haemolysates --- p.42 / Chapter 3.5.4 --- Determination of the Lithium Concentration in Haemolysates --- p.43 / Chapter 3.5.5 --- Determination of Lithium Efflux --- p.43 / Chapter 3.5.6 --- Evaluation of Lithium Efflux Rate --- p.43 / Chapter 3.5.7 --- Evaluation of Intracellular Lithium Concentration --- p.44 / Chapter 3.6 --- VALIDATION OF METHODOLOGY FOR DETERMINATION OF ERYTHROCYTE SODIUM TRANSPORT SYSTEMS --- p.45 / Chapter 3.6.1 --- Effect of Time Course of Lithium Efflux --- p.45 / Chapter 3.6.2 --- Intracellular Potassium Concentration and Its Effect on Ouabain- and Frusemide-Resistant Passive Potassium Efflux --- p.45 / Chapter 3.7 --- PRESERVATION OF ERYTHROCYTES FOR DETERMINATION OF SODIUM TRANSPORT SYSTEMS --- p.51 / Chapter 3.8 --- PRECISION OF THE METHOD --- p.51 / Chapter 3.9 --- STATISTICS --- p.52 / Chapter CHAPTER 4: --- RESULTS --- p.56 / Chapter 4.1 --- POPULATION CHARACTERISTICS --- p.57 / Chapter 4.2 --- ERYTHROCYTE INTRACELLULAR LITHIUM CONCENTRATIONS AFTER LITHIUM LOADING --- p.57 / Chapter 4.3 --- RELATIONSHIP BETWEEN ERYTHROCYTE ION TRANSPORT PARAMETERS AND OTHER VARIABLES --- p.58 / Chapter 4.4 --- ERYTHROCYTE SODIUM TRANSPORT SYSTEMS IN ESSENTIAL HYPERTENSION --- p.64 / Chapter 4.5 --- ERYTHROCYTE SODIUM TRANSPORT SYSTEMS IN PATIENTS WITH DIABETES MELLITUS --- p.64 / Chapter 4.5.1 --- NIDDM Patients without Hypertension --- p.64 / Chapter 4.5.2 --- NIDDM Patients with Hypertension --- p.65 / Chapter 4.5.3 --- NIDDM Patients with and without Hypertension --- p.65 / Chapter 4.6 --- ERYTHROCYTE SODIUM TRANSPORT SYSTEMS IN DIABETES MELLITUS PATIENTS WITH PROTEINURIA --- p.65 / Chapter 4.6.1 --- Clinical Features and Biochemistry Indices --- p.69 / Chapter 4.6.2 --- Ion Transport Systems and NIDDM Patients with Proteinuria --- p.69 / Chapter 4.7 --- EFFECTS OF TREATMENTS ON ERYTHROCYTE ION TRANSPORT SYSTEMS IN DIABETIC HYPERTENSIVE PATIENTS --- p.70 / Chapter 4.7.1 --- Effects of Diuretic Therapy --- p.70 / Chapter 4.7.2 --- Effects of Enalapril and Nifedipine Therapy --- p.74 / Chapter 4.7.3 --- Effects of Enalapril Therapy --- p.74 / Chapter 4.7.4 --- Effects of Nifedipine Therapy --- p.75 / Chapter 4.7.5 --- Comparison of the Effects of Enalapril and Nifedipine Therapy --- p.75 / Chapter CHAPTER 5: --- DISCUSSION --- p.81 / Chapter 5.1 --- SODIUM TRANSPORT IN ESSENTIAL HYPERTENSION --- p.82 / Chapter 5.1.1 --- Erythrocyte Sodium-Lithium Countertransport in Essential Hypertension --- p.82 / Chapter 5.1.2 --- Erythrocyte Sodium-Potassium Cotransport in Essential Hypertension --- p.86 / Chapter 5.1.3 --- Erythrocyte Intracellular Concentration of Sodiumin Essential Hypertension --- p.87 / Chapter 5.1.4 --- Erythrocyte Passive Potassium Efflux in Essential Hypertension --- p.90 / Chapter 5.2 --- SODIUM TRANSPORT SYSTEMS IN NON-INSULIN- DEPENDENT DIABETES MELLITUS (NIDDM) --- p.91 / Chapter 5.2.1 --- Sodium-Lithium Countertransport in Non-Insulin-Dependent Diabetes Mellitus --- p.91 / Chapter 5.2.2 --- Erythrocyte Lithium-Potassium Cotransport and Intracellular Sodium Concentration in Non-Insulin-Dependent Diabetes Mellitus --- p.93 / Chapter 5.3 --- EFFECT OF ANTIHYPERTENSIVE AGENTS ON ERYTHROCYTE SODIUM TRANSPORT SYSTEMS --- p.95 / REFERENCES --- p.98

Wong, Wing Tak Jack. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 204-227). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

A hipertensão arterial (HA) é uma doença multifatorial na qual há a interação de vários mecanismos, e está relacionada com alterações funcionais e/ou estruturais dos órgãos-alvo. Alterações funcionais dos mecanismos regulatórios da pressão arterial (PA) a curto prazo, como os barorreceptores e os quimiorreceptores, vem sendo bastante exploradas com o objetivo de entender os possíveis mecanismos que podem estar relacionadas à gênese da HA. Diante disso, utilizamos o modelo experimental de desnervação sinoaórtica (DSA) e desnervação seletiva desses aferentes (aórtica DA) e/ou carotídea (DC) e a ligadura da artéria do corpúsculo carotídeo (LA) para avaliarmos a importância relativa dos barorreceptores e quimioreceptores no controle neurogênico da circulação mediando respostas cardíacas e músculo-esqueléticas na HA. Para tanto, utilizamos ratos Wistar (CTR) e espontaneamente hipertensos (SHR) submetidos às diferentes desnervações (SHRDSA/ SHRDA / SHRDC), bem como, a ligadura da artéria do corpúsculo carotídeo (SHRLA). Os animais foram acompanhados durante 10 semanas após as desnervações seletivas, e em seguida foram realizadas as avaliações ecocardiográficas, gasometria arterial, hemodinâmicas, autonômicas e de fluxo sanguíneo regional. Posteriormente, os animais foram eutanasiados para a coleta dos tecidos para as avaliações gênicas e histológicas. Resultados: Os animais SHR apresentaram disfunções hemodinâmicas, autonômicas e gasométricas (alcalose respiratória) quando comparado ao grupo CTR, assim como nas análises de hipertrofia, fluxo e histologia do músculo esquelético, como transição no fenótipo para um perfil mais glicolítico no sóleo e aumento da área de secção transversa das fibras do tipo I e redução das fibras do tipo IIB no músculo diafragma. Nos grupos experimentais hipertensos, os animais com prejuízo do quimiorreflexo (SHRDC, SHRLA e SHRDSA), apresentaram valores maiores de pCO2 em relação ao grupo SHR e SHRDA. Todos os grupos com as diferentes desnervações apresentaram alterações autonômicas, de fluxo sanguíneo e de capilarização. Entretanto, nossos maiores achados foram em relação ao grupo SHRDA, que apresentou valores significativamente maiores que o grupo SHR nos parâmetros PAS (212±2 vs 200±3), PAD (156±4 vs 144±3) PAM (185±9 vs 172±3) e FC (377±4 vs 350±7). Além disso, apresentou aumento da variabilidade da PA (VPAS), bem como o simpático periférico (BFPAS), contrariamente ao observado nos grupos SHRDC e SHRLA em relação ao grupo SHR. No controle autonômico da FC, o grupo SHRDA apresentou menor efeito parassimpático e maior efeito simpático em relação ao grupo SHR. Já os grupos SHRDC e SHRLA apresentaram um menor efeito parassimpático, sem alterações no efeito simpático, embora a resistência vascular periférica estivesse aumentada no grupo SHRLA. As adaptações morfofuncionais cardíacas (ecocardiografia e marcadores de hipertrofia cardíaca) foram mais evidentes no grupo que apresentava disfunção total de ambos receptores (SHRDSA). Conclusão: A ausência do controle reflexo exercido predominantemente pelos barorreceptores arteriais demonstrou uma maior influência do componente aórtico do que o carotídeo sobre a PA. Em adição, a função sistólica parece maior nos grupos SHRDA e SHRDSA, sugerindo que a desnervação aórtica esteja associada com ativação simpática. Não se observou alteração cardíaca na desnervação carotídea. Em relação ao músculo esquelético, todas as desnervações mostraram aumento de capilarização, enquanto somente o grupo SHRDSA mostrou redução de fibras intermediárias. O aumento de capilarização pode estar associado com a liberação do simpático periférico nas desnervações que incluem a retirada dos barorreceptores aórticos, levando ao aumento de VPA e à ausência dos quimiorreceptores nos grupos com desaferentação dos receptores carotídeos / Arterial hypertension (AH) is a multifactorial disease on which there is the interaction of several mechanisms , therefore is related to functional and / or structural changes of the target organ . Functional changes of the regulatory mechanisms of blood pressure (BP) in the short term , as pressoreceptor and chemoreceptors, has been extensively explored in order to understand the possible mechanisms that may be related to the genesis of hypertension. Thus, we used the experimental model of sinoaortic denervation (DSA) and selective denervation of those afferent aortic (DA) and / or carotid (DC) and the ligature of the carotid body artery (LA) to evaluate the relative importance of baroreceptors and chemoreceptors on control of neurogenic circulation mediating cardiac and musculoskeletal responses in HA. There by, we used Wistar rats (CTR) and spontaneously hypertensive rats (SHR) subjected to different denervation (SHRDSA / SHRDA / SHRDC) and the ligature of the carotid body artery (SHRLA). The animals were followed for 10 weeks after the selective denervation it was performed echocardiographic evaluations, blood gas, hemodynamic, autonomic and regional blood flow. Subsequently, the animals were euthanized for tissue collection for genetic and histological evaluations. Results: SHR animals showed hemodynamic, autonomic dysfunction and gas exchange (respiratory alkalosis) compared to CTR group as well as the analysis of hypertrophy, flow and histology of skeletal muscle, such as the transition to a more glycolytic phenotype profile in soleus and increased cross-sectional area of type I fibers and reduction of type IIB fibers in the diaphragm . In hypertensive experimental groups, animals with prejudice chemoreflex (SHRDC, SHRLA and SHRDSA) , showed higher pCO2 compared to SHR and SHRDA group. All groups with different denervation showed autonomic changes in blood flow and capillarization. However, our major findings were compared to SHRDA group, which was significantly higher than the SHR in SBP (212 ± 2 vs 200 ± 3), DBP (156 ± 4 vs 144 ± 3), MAP (185 ± 9 vs 172 ± 3) and HR (377 ± 4 vs 350 ± 7) parameters. Furthermore, we showed an increase in BP variability (BPV) and in the peripheral sympathetic (BFPAS), otherwise showed in the groups SHRDC and SHRLA compared to SHR . Autonomic control of HR, the SHRDA group showed lower sympathetic and higher parasympathetic effect effect in relation to SHR. Already SHRDC and SHRLA groups had a lower parasympathetic effect without changes in sympathetic, although peripheral vascular resistance was increased in SHRLA group. The cardiac morphofunctional adaptations (echocardiography and cardiac hypertrophy markers) were more evident in the group that had total dysfunction of both receptors (SHRDSA). Conclusion: The absence of reflex control exerted by arterial baroreceptors predominantly showed a greater influence of the aortic component of the carotid on BP. In addition, systolic function appears higher in groups SHRDA and SHRDSA, suggesting that aortic denervation is associated with sympathetic activation. No cardiac abnormality was observed in the carotid denervation. Regarding skeletal muscle, all denervations showed an increased of capillarization, while only SHRDSA group showed reduction of intermediate fibers. Increased capillarization may be associated with the release of the peripheral sympathetic denervation, including removal of the aortic baroreceptors, leading to increased VPA and the absence of chemoreceptors in groups with deafferentation of the carotid receptors

A hipertensão arterial (HA) é uma doença multifatorial na qual há a interação de vários mecanismos, e está relacionada com alterações funcionais e/ou estruturais dos órgãos-alvo. Alterações funcionais dos mecanismos regulatórios da pressão arterial (PA) a curto prazo, como os barorreceptores e os quimiorreceptores, vem sendo bastante exploradas com o objetivo de entender os possíveis mecanismos que podem estar relacionadas à gênese da HA. Diante disso, utilizamos o modelo experimental de desnervação sinoaórtica (DSA) e desnervação seletiva desses aferentes (aórtica DA) e/ou carotídea (DC) e a ligadura da artéria do corpúsculo carotídeo (LA) para avaliarmos a importância relativa dos barorreceptores e quimioreceptores no controle neurogênico da circulação mediando respostas cardíacas e músculo-esqueléticas na HA. Para tanto, utilizamos ratos Wistar (CTR) e espontaneamente hipertensos (SHR) submetidos às diferentes desnervações (SHRDSA/ SHRDA / SHRDC), bem como, a ligadura da artéria do corpúsculo carotídeo (SHRLA). Os animais foram acompanhados durante 10 semanas após as desnervações seletivas, e em seguida foram realizadas as avaliações ecocardiográficas, gasometria arterial, hemodinâmicas, autonômicas e de fluxo sanguíneo regional. Posteriormente, os animais foram eutanasiados para a coleta dos tecidos para as avaliações gênicas e histológicas. Resultados: Os animais SHR apresentaram disfunções hemodinâmicas, autonômicas e gasométricas (alcalose respiratória) quando comparado ao grupo CTR, assim como nas análises de hipertrofia, fluxo e histologia do músculo esquelético, como transição no fenótipo para um perfil mais glicolítico no sóleo e aumento da área de secção transversa das fibras do tipo I e redução das fibras do tipo IIB no músculo diafragma. Nos grupos experimentais hipertensos, os animais com prejuízo do quimiorreflexo (SHRDC, SHRLA e SHRDSA), apresentaram valores maiores de pCO2 em relação ao grupo SHR e SHRDA. Todos os grupos com as diferentes desnervações apresentaram alterações autonômicas, de fluxo sanguíneo e de capilarização. Entretanto, nossos maiores achados foram em relação ao grupo SHRDA, que apresentou valores significativamente maiores que o grupo SHR nos parâmetros PAS (212±2 vs 200±3), PAD (156±4 vs 144±3) PAM (185±9 vs 172±3) e FC (377±4 vs 350±7). Além disso, apresentou aumento da variabilidade da PA (VPAS), bem como o simpático periférico (BFPAS), contrariamente ao observado nos grupos SHRDC e SHRLA em relação ao grupo SHR. No controle autonômico da FC, o grupo SHRDA apresentou menor efeito parassimpático e maior efeito simpático em relação ao grupo SHR. Já os grupos SHRDC e SHRLA apresentaram um menor efeito parassimpático, sem alterações no efeito simpático, embora a resistência vascular periférica estivesse aumentada no grupo SHRLA. As adaptações morfofuncionais cardíacas (ecocardiografia e marcadores de hipertrofia cardíaca) foram mais evidentes no grupo que apresentava disfunção total de ambos receptores (SHRDSA). Conclusão: A ausência do controle reflexo exercido predominantemente pelos barorreceptores arteriais demonstrou uma maior influência do componente aórtico do que o carotídeo sobre a PA. Em adição, a função sistólica parece maior nos grupos SHRDA e SHRDSA, sugerindo que a desnervação aórtica esteja associada com ativação simpática. Não se observou alteração cardíaca na desnervação carotídea. Em relação ao músculo esquelético, todas as desnervações mostraram aumento de capilarização, enquanto somente o grupo SHRDSA mostrou redução de fibras intermediárias. O aumento de capilarização pode estar associado com a liberação do simpático periférico nas desnervações que incluem a retirada dos barorreceptores aórticos, levando ao aumento de VPA e à ausência dos quimiorreceptores nos grupos com desaferentação dos receptores carotídeos / Arterial hypertension (AH) is a multifactorial disease on which there is the interaction of several mechanisms , therefore is related to functional and / or structural changes of the target organ . Functional changes of the regulatory mechanisms of blood pressure (BP) in the short term , as pressoreceptor and chemoreceptors, has been extensively explored in order to understand the possible mechanisms that may be related to the genesis of hypertension. Thus, we used the experimental model of sinoaortic denervation (DSA) and selective denervation of those afferent aortic (DA) and / or carotid (DC) and the ligature of the carotid body artery (LA) to evaluate the relative importance of baroreceptors and chemoreceptors on control of neurogenic circulation mediating cardiac and musculoskeletal responses in HA. There by, we used Wistar rats (CTR) and spontaneously hypertensive rats (SHR) subjected to different denervation (SHRDSA / SHRDA / SHRDC) and the ligature of the carotid body artery (SHRLA). The animals were followed for 10 weeks after the selective denervation it was performed echocardiographic evaluations, blood gas, hemodynamic, autonomic and regional blood flow. Subsequently, the animals were euthanized for tissue collection for genetic and histological evaluations. Results: SHR animals showed hemodynamic, autonomic dysfunction and gas exchange (respiratory alkalosis) compared to CTR group as well as the analysis of hypertrophy, flow and histology of skeletal muscle, such as the transition to a more glycolytic phenotype profile in soleus and increased cross-sectional area of type I fibers and reduction of type IIB fibers in the diaphragm . In hypertensive experimental groups, animals with prejudice chemoreflex (SHRDC, SHRLA and SHRDSA) , showed higher pCO2 compared to SHR and SHRDA group. All groups with different denervation showed autonomic changes in blood flow and capillarization. However, our major findings were compared to SHRDA group, which was significantly higher than the SHR in SBP (212 ± 2 vs 200 ± 3), DBP (156 ± 4 vs 144 ± 3), MAP (185 ± 9 vs 172 ± 3) and HR (377 ± 4 vs 350 ± 7) parameters. Furthermore, we showed an increase in BP variability (BPV) and in the peripheral sympathetic (BFPAS), otherwise showed in the groups SHRDC and SHRLA compared to SHR . Autonomic control of HR, the SHRDA group showed lower sympathetic and higher parasympathetic effect effect in relation to SHR. Already SHRDC and SHRLA groups had a lower parasympathetic effect without changes in sympathetic, although peripheral vascular resistance was increased in SHRLA group. The cardiac morphofunctional adaptations (echocardiography and cardiac hypertrophy markers) were more evident in the group that had total dysfunction of both receptors (SHRDSA). Conclusion: The absence of reflex control exerted by arterial baroreceptors predominantly showed a greater influence of the aortic component of the carotid on BP. In addition, systolic function appears higher in groups SHRDA and SHRDSA, suggesting that aortic denervation is associated with sympathetic activation. No cardiac abnormality was observed in the carotid denervation. Regarding skeletal muscle, all denervations showed an increased of capillarization, while only SHRDSA group showed reduction of intermediate fibers. Increased capillarization may be associated with the release of the peripheral sympathetic denervation, including removal of the aortic baroreceptors, leading to increased VPA and the absence of chemoreceptors in groups with deafferentation of the carotid receptors