The study applies in vivo technique for profiling hemodynamics and wall shear stress (WSS) distribution in human coronary arteries. The methodology involves fusion of 2D Intra Vascular Ultra Sound and Bi-plane angiograms to reproduce the 3D arterial geometry. This geometry is then used in a Computational Fluid Dynamics (CFD) module for flow modeling. The Walburn and Schneck constitutive relation was used to represent the non-Newtonian blood rheology. The methodology is applied to study the relationship between WSS and Neointimal Hyperplasia (NIH) in two groups of diabetic patients after being treated separately with bare metal stents (BMS) and Sirolimus Eluting Stents (SES). The stent assignments were blinded until the end of the study. The study was repeated for the patients after 9 months. The predicted WSS ranged from (0.1- 8 N/m2) and was categorized into five classes: low ( < 1 N/m2); low-normal (1-2 N/m2); normal (2-3 N/m2); high-normal (3-4 N/m2); high ( > 4 N/m2). The results indicate NIH in 5 of the patients treated with BMS and none in SES cases. These results correlate with our predicted WSS distribution.

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / O desenvolvimento da programação fetal é considerado um importante fator de risco para doenças não-transmissíveis da vida adulta, incluindo doença cardíaca coronariana. Com o objetivo de investigar a associação entre nutrição materna e o desenvolvimento das artérias coronárias (AC) em embriões de camundongos estadiados; embriões de camundongos C57BL/6 nos estádios de 16-23 foram retirados de mães alimentadas com dietas de proteína normal (NP) ou de baixa proteína (LP), e as AC foram estudadas. Embora os embriões LP possuam massa corporal menor, entretanto tinham taxas de crescimento cardíaco maior, quando comparados com os embriões NP. O Plexo subepicárdico foi observado no início do período pós-somítico (estádio 16) de embriões NP, enquanto que nos embriões LP apenas no estádio 17 (P <0,01), persistindo até o estádio 18 (P <0,01). As artérias coronárias foram detectadas inicialmente no estádio18 dos embriões NP, já nos embriões LP foram encontradas a partir do estádio 19 (P <0,01). Núcleos apoptóticos foram observados em torno do anel aórtico peritruncal no estádio 18 em embriões NP e LP. Células FLK1+ (Fetal Liver Kinase 1 = VEGFr2 = Vascular Endothelial Growth Factor Receptor 2) apresentaram uma distribuição homogênea nos embriões NP já no estádio 18, enquanto uma distribuição semelhante nos embriões LP foi visto apenas nos estádios 22 e 23. A restrição proteica materna em camundongos leva a um atraso no crescimento do coração no período embrionário modificando o desenvolvimento do plexo peritruncal subepicárdica e diminuindo a taxa de apoptose na região do futuro orifício coronariano. / Programming of fetal development is considered to be an important risk factor for non-communicable diseases of adulthood, including coronary heart disease (CHD). Aiming to investigate the association between maternal nutrition and the development of the coronary arteries (CA) in staged mice embryos, C57BL/6 mice embryos from stages 16 to 23 were taken from mothers fed a normal protein (NP) or low protein (LP) diet, and the CA were studied. Although the LP embryos had lower masses, they had faster heart growth rates when compared to the NP embryos. The subepicardial plexuses were observed earlier in the NP embryos (stage 20) than in the LP ones (stage 22) (P<0.01). Apoptotic nuclei were seen around the aortic peritruncal ring beginning at stage 18 in the NP and LP embryos. FLK1+ (fetal liver kinase 1 = VEGFr2 or vascular endothelial growth factor receptor 2) cells had a homogeneous distribution in the NP embryos as early as stage 18, whereas a similar distribution in the LP embryos was only seen at stages 22 and 23. Maternal protein restriction in mice leads to a delay in the growth of the heart in the embryonic period modifying the development of the subepicardial peritruncal plexus and the apoptosis in the future coronary orifice region.

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / O desenvolvimento da programação fetal é considerado um importante fator de risco para doenças não-transmissíveis da vida adulta, incluindo doença cardíaca coronariana. Com o objetivo de investigar a associação entre nutrição materna e o desenvolvimento das artérias coronárias (AC) em embriões de camundongos estadiados; embriões de camundongos C57BL/6 nos estádios de 16-23 foram retirados de mães alimentadas com dietas de proteína normal (NP) ou de baixa proteína (LP), e as AC foram estudadas. Embora os embriões LP possuam massa corporal menor, entretanto tinham taxas de crescimento cardíaco maior, quando comparados com os embriões NP. O Plexo subepicárdico foi observado no início do período pós-somítico (estádio 16) de embriões NP, enquanto que nos embriões LP apenas no estádio 17 (P <0,01), persistindo até o estádio 18 (P <0,01). As artérias coronárias foram detectadas inicialmente no estádio18 dos embriões NP, já nos embriões LP foram encontradas a partir do estádio 19 (P <0,01). Núcleos apoptóticos foram observados em torno do anel aórtico peritruncal no estádio 18 em embriões NP e LP. Células FLK1+ (Fetal Liver Kinase 1 = VEGFr2 = Vascular Endothelial Growth Factor Receptor 2) apresentaram uma distribuição homogênea nos embriões NP já no estádio 18, enquanto uma distribuição semelhante nos embriões LP foi visto apenas nos estádios 22 e 23. A restrição proteica materna em camundongos leva a um atraso no crescimento do coração no período embrionário modificando o desenvolvimento do plexo peritruncal subepicárdica e diminuindo a taxa de apoptose na região do futuro orifício coronariano. / Programming of fetal development is considered to be an important risk factor for non-communicable diseases of adulthood, including coronary heart disease (CHD). Aiming to investigate the association between maternal nutrition and the development of the coronary arteries (CA) in staged mice embryos, C57BL/6 mice embryos from stages 16 to 23 were taken from mothers fed a normal protein (NP) or low protein (LP) diet, and the CA were studied. Although the LP embryos had lower masses, they had faster heart growth rates when compared to the NP embryos. The subepicardial plexuses were observed earlier in the NP embryos (stage 20) than in the LP ones (stage 22) (P<0.01). Apoptotic nuclei were seen around the aortic peritruncal ring beginning at stage 18 in the NP and LP embryos. FLK1+ (fetal liver kinase 1 = VEGFr2 or vascular endothelial growth factor receptor 2) cells had a homogeneous distribution in the NP embryos as early as stage 18, whereas a similar distribution in the LP embryos was only seen at stages 22 and 23. Maternal protein restriction in mice leads to a delay in the growth of the heart in the embryonic period modifying the development of the subepicardial peritruncal plexus and the apoptosis in the future coronary orifice region.

Thesis (M.Tech.: Radiography)-Dept. of Radiography, Durban University of Technology, 2008. xxi, 146 leaves, Appendices A-S / The main aim of this study, was to assess the prevalence of coronary artery calcification in asymptomatic risk and non risk individuals in the South African Indian population, within the age group of 20-70 years.

Effet de l’atorvastatine sur la dysfonction endothéliale des artères coronaires épicardiques associée à l’hypertrophie ventriculaire gauche dans un modèle porcin Forcillo J, Aubin MC, Horn A, Shi YF, Carrier M, Tardif JC, Perrault LP Introduction: L’atorvastatine par ses effets pléiotropiques pourrait limiter la dysfonction endothéliale associée au développement de l’HVG. Méthodologie : Un cerclage de l’aorte ascendante pendant 2 mois entraîne le développement d’HVG et les groupes ont été traités avec atorvastatine 40 ou 80 mg de 60 à 90 jours. L’HVG est confirmée par échographie. La réactivité vasculaire est évaluée en chambres d’organe, la fonction endothéliale par la quantification de la GMPc et des nitrites/nitrates plasmatiques. Le stress oxydant est mesuré par les niveaux d’ANG II et de la carbonylation des protéines. Résultats : Après 60 et 90 j de cerclage, l’HVG est observée chez tous ces groupes. Les courbes concentrations-réponse des anneaux des artères coronaires épicardiques des groupes traités avec l’atorvastatine 40 et 80 mg pour 30 et 60 jours n’ont démontré aucune amélioration des relaxations dépendantes de l’endothélium. Une exacerbation significative de la dysfonction endothéliale a été observée. Les niveaux vasculaires de GMPc sont significativement diminués dans le groupe sans cerclage traité 60 d et ceux d’ANG II sont fortement augmentés chez ce dernier groupe ainsi que le groupe traité avec 80 mg pour 30 jours par rapport aux contrôles. L’expression de la carbonylation des protéines est augmentée dans le groupe témoin traité avec atorvastatine 80 mg, reflétant une augmentation du stress oxydant. Conclusion : L’administration d’atorvastatine ne prévient pas le développement de l’HVG ni la dysfonction endothéliale dans notre modèle. Au contraire l’atorvastatine à haute dose a un effet toxique sur les artères coronaires épicardiques en augmentant la dysfonction endothéliale. / Effect of atorvastatin on endothelial dysfunction of epicardial coronary arteries associated with left ventricular hypertrophy in a porcine model. Forcillo J, Aubin MC, Horn A, Shi YF, Carrier M, Tardif JC, Perrault LP Background: Atorvastatin, through pleiotropic effects, may prevent or reverse the endothelial dysfunction associated with LVH. Methods: After performing a banding of the ascending aorta for 2 months leading to the development of LVH, groups have been treated with atorvastatin 40 or 80 mg for 60 and 90 day periods. LVH was evaluated by echocardiographic studies. Vascular reactivity studies were performed in organ chambers. In vitro endothelial function was evaluated by plasmatic nitrites/nitrates, the degradations products of nitric oxide, and cGMP quantification. To quantify and qualify oxidative stress, protein carbonyl and angiotensin II levels were assessed. Results: Following 60 and 90 days of aortic banding, the development of LVH was observed in these groups. Concentration-response curves from rings of epicardial coronary arteries of groups treated with atorvastatin 40 and 80 mg for 30 and 60 days showed a significant decrease of endothelium-dependent relaxations with worsening of the endothelial dysfunction. Levels of cGMP were significantly decreased in the 60 days treated sham group and levels of ANG II were increased in the latter and also in the 90 days banded groups treated with 80 mg for 30 days compared to controls. The expression of protein carbonyl increased in the sham group treated with atorvastatin 80 mg compatible with an increase in oxidative stress. Conclusion: The administration of atorvastatin does not limit the development of LVH nor the endothelial dysfunction in our model. On the opposite, atorvastatin at a high dose has a toxic effect on epicardial coronary arteries by exacerbating the endothelial dysfunction.

Thesis submitted in fulfilment of the requirements of the Master's Degree in technology: Radiography, Durban University of Technology, 2008. / The main aim of this study, was to assess the prevalence of coronary artery calcification in asymptomatic risk and non risk individuals in the South African Indian population, within the age group of 20-70 years. / M

De nos jours, les progrès de l’informatisation de l’imagerie médicale assistent au plus près les médecins dans leur soin au patient. Des modèles personnalisés computationnels sont utilisés pour le diagnostique, prognostique et planification du traitement, en diminuant lesrisques pour le patient, et potentiellement les frais médicaux.Heartflow est l’exemple même d’une compagnie qui réussit ce service dans le domaine cardiovasculaire. À partir d’un modèle extrait d’images tomographiques rayons X, les lésions avec impact fonctionnel sont identifiées dans les artères coronaires. Cette analyse qui combine l’anatomie à la fonction est néanmoins limitée par la résolution de l’image. En aval de ces larges vaisseaux, un examen fonctionnel dénommé Imagerie de Perfusion du Myocarde (IPM) met en évidence les régions du myocarde affectées par un déficit de flux sanguin. Cependant, l’IPM n’établie pas de relation fonctionnelle avec les larges vaisseaux coronaires lésés en amont.L’objectif de ce projet est de construire la connexion fonctionnelle entre les coronaires et le myocarde, en extrapolant l’analyse fonctionnelle depuis les larges vaisseaux vers le lit capillaire. À cette fin, il faut étendre le modèle vasculaire jusqu'aux microvaisseaux, et mener une analyse fonctionnelle en direction du comportement myocardique.Nous étendons une méthode de génération d’arbre vasculaire basée sur la satisfaction de principes fonctionnels, nommée Constrained Constructive Optimization (Optimization Constructive sous Contraintes), pour qu’elle s’applique à de multiples arbres vasculaires en compétition. L’algorithme simule l’angiogénèse avec minimisation du volume vasculaire sous contraintes de flux et de géométrie adaptant la croissance simultanée des arbres aux caractéristiques du patient. Cette méthode fournit un modèle hybride composé de coronaires épicardiales extraites d’images et de vaisseaux synthétiques jusqu’aux artérioles, emplissant le ventricule gauche du myocarde.Puis, nous construisons un pipeline d’analyse fonctionnelle multi-échelle pour étendre la simulation de flux depuis les coronaires vers le myocarde. Cela consiste en un modèle de flux coronaire 1D compatible avec la vasculature hybride, et l’analyse de la distribution spatiale des flux provenant des segments terminaux. Cette dernière est réalisée dans une nomenclature similaire à celle de l’IPM pour permettre la comparaison avec des données de vérité terrain fonctionnelles.Nous avons relié l’anatomie du réseau vasculaire à la distribution de flux dans le myocarde pour plusieurs patients. Cette analyse multi-échelle permet d’identifier des pistes pour affiner les méthodes de génération vasculaire et de simulation de flux. Cette extrapolation anatomique et fonctionnelle personnalisée est une première passerelle pour la simulation de perfusion du myocarde à partir d’imagerie tomographique scanner. La construction d’un tel modèle computationnel personnalisé pourrait aider à la compréhension de la physio-pathologie cardiovasculaire complexe et, enfin, à la santé du patient. / Recent advances in medical image computing have allowed automatedsystems to closely assist physicians in patient therapy. Computationaland personalized patient models benefit diagnosis, prognosisand treatment planning, with a decreased risk for the patient,as well as potentially lower cost. HeartFlow Inc. is a successfull exampleof a company providing such a service in the cardiovascularcontext. Based on patient-specific vascular model extracted from XrayCT images, they identify functionally significant disease in largecoronary arteries. Their combined anatomical and functional analysisis nonetheless limited by the image resolution. At the downstreamscale, a functional exam called Myocardium Perfusion Imaging (MPI)highlights myocardium regions with blood flow deficit. However,MPI does not functionally relate perfusion to the upstream coronarydisease.The goal of our project is to build the functional bridge betweencoronary and myocardium, by extrapolating the functional analysisfrom large coronary toward the capillary bed. This objective requiresextension from the coronary model down to the microvasculaturecombined with a functional analysis leading to the myocardium compartment.We expand a tree generation method subjected to functional principles,named Constrained Constructive Optimization, to generate multiplecompeting vascular trees. The algorithm simulates angiogenesisunder vascular volume minimization with flow-related and geometricalconstraints, adapting the simultaneous tree growths to patientpriors. This method provides a hybrid image-based and synthetic geometricmodel, starting from segmented epicardium coronary downto synthetic arterioles, filling the left ventricle myocardium.We then build a multiscale functional analysis pipeline to allowblood flow simulation from the coronaries to the myocardium. Thisis achieved with a 1D coronary model compatible with the hybridvasculature, and a spatial blood flow distribution analysis of the terminalsegments. The latter is performed using a similar nomenclatureto MPI, to enable patient-specific comparison with functional groundtruthdata.We connected the vascular anatomy to blood flow distribution inthe myocardium on several patient datasets. This multiscale frameworkpoints out several leads to refine the vascular network generationand fluid simulation methods. This patient-specific anatomicaland functional extrapolation is a first gateway toward myocardiumperfusion from X-ray CT data. Building such personalized computational model of patient could potentially help investigating cardiovascularcomplex physio-pathology, and, finally, improve the patientcare.

O endotélio vascular é responsável por várias funções, dentre elas, o controle do tônus vascular realizado por meio da produção e liberação de substâncias constritoras (EDCFs) e relaxantes (EDRFs) derivadas das células endoteliais. Essas substâncias então envolvidas em várias ações como relaxamento ou contração do músculo liso vascular. Em algumas doenças como na hipertensão arterial, ocorre um desequilíbrio entre esses mecanismos. Essas alterações podem ocorrer devido ao aumento nas concentrações de espécies reativas de oxigênio (EROs) que reduzem a biodisponibilidade do óxido nítrico (NO), principal EDRF, assim como aumentar os níveis de prostanóides como prostaglandinas (PGs) e tromboxano A2 (TXA2), principais EDCFs produzidos pela COX. Dessa forma, a liberação de NO e inibição da COX podem ser efetivas nesses casos. Os anti-inflamatórios não esteroidais associados a doadores de NO (CINODs) tem importantes ações no sistema vascular. O leito vascular coronariano pode sofrer com o desequilíbrio na produção de fatores endoteliais e apresentar disfunção endotelial. Porém, apesar da sua relevância, a microcirculação coronariana não tem sido explorada como alvo para os CINODs. O presente trabalho teve como objetivo avaliar as alterações vasculares do leito coronariano no modelo de hipertensão renal (2R-1C) e determinar a ação do composto NCX 2121 em artéria coronária de ratos normotensos (2R) e hipertensos 2R-1C. Observamos alterações cardíacas com hipertrofia do coração e menor aumento da pressão de perfusão coronariana (PPC) sob aumentos de fluxo, pela técnica de Langendorff em corações de 2R-1C. Na artéria coronária isolada houve aumento da expressão da enzima cicloxigenase (COX-2), redução na expressão de Cav-1 e em canais para potássio, ausência de disfunção endotelial e redução na resposta contrátil ao agonista do receptor TP (U46619) mediada pela atividade de COX, bem como resposta relaxante dependente do endotélio também dependente de COX em 2R-1C. Ainda o U46619 induziu uma grande produção de PGI2 somente em artérias coronárias de 2R-1C. O composto NCX2121 promoveu relaxamento de baixa magnitude em artérias coronárias, sem diferenças entre a resposta entre artérias de ratos 2R e 2R-1C e sem a participação de EROs. Verificamos que o L-NAME induziu um ganho de contração nas artérias dependente de atividade de COX. . Nossos resultados sugerem que durante a hipertensão a via da COX com produção de PGI2 pode estar aumentada justificando a baixa magnitude de relaxamento ao composto NCX2121, um inibidor de COX / as prostaglandins (PGs) and thromboxane A2 (TXA2) the main EDCFs produced by COX. Thus, NO release and COX inhibition may be effective in these cases. Non-steroidal anti-inflammatory drugs associated with NO donors (CINODs) have important actions in the vascular system. The imbalance between the production of endothelial factors is recognized as endothelial dysfunction. However, despite its relevance the coronary microcirculation has not been explored as a target for CINODs. The objective of this study was to evaluate the vascular alterations of the coronary vascular bed in renovascular hypertension model (2K-1C) and determine the action of the compound NCX 2121. We observed cardiac changes with hypertrophy of the heart and lower increase of coronary perfusion pressure (CPP) under increases of flow, by the Langendorff technique in 2K-1C hearts. In the isolated coronary artery there was an increase in the expression of the cyclooxygenase 2 (COX-2) enzyme, reduction in Cav-1 expression and in potassium channels, absence of endothelial dysfunction and reduction in the contractile response to TP-receptor agonist (U46619) mediated by COX activity, as well as endothelium-dependent relaxing response dependent of COX in 2K-1C. Furthermore, U46619 induced a large production of PGI2 only in 2R-1C coronary arteries. The compound NCX2121 promoted low magnitude relaxation in coronary arteries with no differences between the arteries from 2K and 2K-1C rats also without participation of EROs. We found L-NAME induced contraction dependent on COX activity in 2K-1C. Our results suggest that during hypertension the COX pathway with PGI2 production may be increased justifying the low magnitude of relaxation to the compound NCX2121, a COX inhibitor.

Ca2+-activated potassium channels (KCa) and canonical transient receptor potential (TRPC) channels are essential to endothelial function. In ischemic heart disease, or in cardiac surgery, coronary endothelium is subjected to ischemia-reperfusion (I-R) / hypoxia-reoxygenation (H-R) injury. Hyperkalemic cardioplegic or organ preservation solutions used in cardiac surgery including heart transplantation also impair endothelial function. The present study was designed to mainly investigate whether endothelial dysfunction occurring in H-R or in hyperkalemic exposure is attributable to alterations of intermediate- and small-conductance KCa (IKCa and SKCa) channels, or TRPC channels, in particular, the TRPC3 channel. / Exposure to 60-min hypoxia followed by reoxygenation inhibited the vasorelaxant response of coronary arteries to IKCa / SKCa activator 1-EBIO. H-R reduced endothelial IKCa and SKCa currents and downregulated IKCa expression in PCECs. 1-EBIO enhanced endothelial K+ current that was blunted by H-R. / Exposure to hyperkalemic solutions decreased Ca2+ influx via TRPC3 in PCECs. The reduced Ca2+ influx in PCECs and the attenuated EDHF-mediated vasorelaxation in porcine coronary arteries, which were caused by hyperkalemic or cardioplegic / organ preservation solutions, were restored by OAG. / In PCECs, hypoxia for 60-min with reoxygenation reduced TRPC3 current and Ca2+ influx via TRPC3, which was accompanied by decreased NO release and endothelium-dependent vasorelaxation of porcine coronary arteries. The compromised endothelial function was restored by OAG. The translocation of TRPC3 to endothelial membrane was inhibited by H-R. / In TRPC3-overexpressing HEK293 cells, followed by reoxygenation, short-time hypoxia (10-min) enhanced, whereas prolonged hypoxia (60-min) reduced the current induced by TRPC3/6/7 activator OAG. / Our results indicate that: (1) Endothelial IKCa, SKCa and TRPC3 play an important role in regulating vascular tone; TRPC3 contributes to NO release from endothelial cells and is also involved in the function of EDHF. (2) H-R (60-30 min) reduces endothelial IKCa and SKCa currents with downregulation ofthe protein expression of IKCa. (3) H-R has dual effect on TRPC3 with short-time hypoxia (lO-min) enhancing whereas prolonged hypoxia (60-min) decreasing the electrophysiological activity of this channel. H-R (60-30 min) inhibits the translocation of TRPC3 to endothelial membrane. Furthermore, H-R inhibits Ca2+ influx via TRPC3 and such inhibition is associated with a decrease of NO production. (4) The activator of IKCa / SKCa or TRPC protects coronary endothelium against H-R injury. In coronary endothelium exposed to hyperkalemic or cardioplegic / organ preservation solutions, TRPC activator also exhibits protective effect. / The above findings are likely to have significant implications in ischemic heart disease and in modem cardiopulmonary surgery. / Whole-cell membrane currents of IKCa, SKCa, or TRPC3 were recorded by patch-clamp in primary cultured porcine coronary endothelial cells (PCECs). TRPC3 current was also studied in human embryonic kidney cells (HEK293 cells) transiently overexpressed with TRPC3 gene. Protein or mRNA expression of these channels was detected by Western blot or RT-PCR. Intracellular Ca2+ concentration was measured by Ca2+ imaging technique. Isometric force study was performed in a wire myograph and endothelial nitric oxide (NO) release was measured electrochemically by using a NO-specific microsensor in porcine coronary small arteries. / Huang, Junhao. / "December 2010." / Adviser: Qin Yang. / Source: Dissertation Abstracts International, Volume: 73-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 138-165). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Wu Min. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 87-114). / Abstracts in English and Chinese. / Declaration --- p.i / Acknowledgement --- p.ii / Publication list --- p.iii / Abstract (English) --- p.xi / Abstract (Chinese) --- p.xiv / Abbreviations --- p.xvi / List of figures / tables --- p.xviii / Chapter Chapter 1. --- General Introduction --- p.1 / Chapter 1.1 --- Endothelial function in the regulation of vascular tone --- p.1 / Chapter 1.1.1 --- NO --- p.2 / Chapter 1.1.2 --- PGI2 --- p.5 / Chapter 1.1.3 --- EDHF --- p.6 / Chapter 1.2 --- Alteration of endothelial functions after preservation with cardioplegia /organ preservation solutions in the coronary and pulmonary microcirculations --- p.18 / Chapter 1.2.1 --- Cardioplegia/organ preservation solutions --- p.21 / Chapter 1.2.2 --- Effect of Cardioplegia/organ preservation solutions on endothelial function --- p.22 / Chapter 1.2.2.1 --- Effect of K+ on endothelial function --- p.23 / Chapter 1.2.2.2 --- Effect of other components on endothelial function --- p.24 / Chapter Chapter 2. --- Materials and Methods --- p.26 / Chapter 2.1 --- Isometric force study in coronary/pulmonary resistance arteries --- p.26 / Chapter 2.1.1 --- Preparation of vessels --- p.26 / Chapter 2.1.1.1 --- Preparation of porcine coronary small arteries --- p.26 / Chapter 2.1.1.2 --- Preparation of porcine pulmonary small arteries --- p.26 / Chapter 2.1.2 --- Technique of setting up --- p.29 / Chapter 2.1.2.1 --- Mounting of small vessels --- p.29 / Chapter 2.1.2.2 --- Normalization procedure for small vessels --- p.29 / Chapter 2.1.3 --- EDHF-mediated vasorelaxation --- p.30 / Chapter 2.1.3.1 --- Precontraction and stimuli of EDHF --- p.30 / Chapter 2.1.3.2 --- """True"" response of EDHF" --- p.31 / Chapter 2.1.4 --- Data acquisition and analysis --- p.32 / Chapter 2.2 --- Electrophysiological study --- p.32 / Chapter 2.2.1 --- Preparation of small porcine coronary/pulmonary arteries --- p.32 / Chapter 2.2.2 --- Preparation of microelectrode --- p.32 / Chapter 2.2.3 --- Impaling of microelectrode --- p.33 / Chapter 2.2.4 --- Recording of membrane potential --- p.33 / Chapter 2.3 --- Statistical analysis --- p.34 / Chapter 2.4 --- Chemicals --- p.34 / Chapter Chapter 3. --- Effects of Celsior Solution on Endothelial Function in Resistance Coronary Arteries Compared to St. Thomas' Hospital Solution --- p.37 / Chapter 3.1 --- Abstract --- p.37 / Chapter 3.2 --- Introduction --- p.38 / Chapter 3.3 --- Experimental design and analysis --- p.40 / Chapter 3.3.1 --- Vessel preparation --- p.40 / Chapter 3.3.2 --- Normalization --- p.40 / Chapter 3:3.3 --- "Relaxation study: BK-induced, EDHF-mediated relaxation" --- p.41 / Chapter 3.3.4 --- Cellular electrophysiological study: EDHF-mediated cellular hyperpolarization and associated relaxation --- p.41 / Chapter 3.3.5 --- Data analysis --- p.42 / Chapter 3.4 --- Results --- p.43 / Chapter 3.4.1 --- Relaxation study --- p.43 / Chapter 3.4.1.1 --- Resting force --- p.43 / Chapter 3.4.1.2 --- U46619-induced precontraction --- p.43 / Chapter 3.4.1.3 --- EDHF-mediated relaxation --- p.43 / Chapter 3.4.2 --- Electrophysiological studies --- p.44 / Chapter 3.4.2.1 --- Resting membrane potential --- p.44 / Chapter 3.4.2.2 --- EDHF-mediated cellular hyperpolarization --- p.45 / Chapter 3.4.2.3 --- Cellular hyperpolarization-associated relaxation --- p.45 / Chapter 3.5 --- Discussion --- p.46 / Chapter 3.5.1 --- Effects of Celsior solution on endothelial function --- p.47 / Chapter 3.5.2 --- Effects of ST solution on EDHF-mediated function --- p.48 / Chapter 3.5.3 --- Comparison between Celsior and ST solutions on EDHF-mediated function --- p.48 / Chapter 3.5.4 --- Clinical implications --- p.49 / Chapter Chapter 4. --- Effects of Perfadex and Celsior Solution on Endothelial Function in Resistance Pulmonary Arteries --- p.57 / Chapter 4.1 --- Abstract --- p.57 / Chapter 4.2 --- Introduction --- p.58 / Chapter 4.3 --- Experimental design and analysis --- p.59 / Chapter 4.3.1 --- Vessel Preparation --- p.59 / Chapter 4.3.2 --- Normalization --- p.60 / Chapter 4.3.3 --- Isometric force study --- p.60 / Chapter 4.3.4 --- Electrophysiological studies --- p.61 / Chapter 4.3.5 --- Data analysis --- p.61 / Chapter 4.4 --- Results --- p.62 / Chapter 4.4.1 --- Relaxation study: EDHF-mediated relaxation --- p.62 / Chapter 4.4.1.1 --- Resting force --- p.62 / Chapter 4.4.1.2 --- U46619-induced precontraction --- p.62 / Chapter 4.4.1.3 --- EDHF-mediated relaxation --- p.62 / Chapter 4.4.2 --- Electrophysiological studies --- p.63 / Chapter 4.4.2.1 --- Resting membrane potential --- p.63 / Chapter 4.4.2.2 --- EDHF-mediated cellular hyperpolarization --- p.64 / Chapter 4.4.2.3 --- Cellular hyperpolarization-associated relaxation --- p.64 / Chapter 4.5 --- Discussion --- p.65 / Chapter 4.5.1 --- Effects of Celsior solution on endothelial function during cardiopulmonary surgery --- p.65 / Chapter 4.5.2 --- Effects of Perfadex solution on EDHF-mediated endothelial function --- p.66 / Chapter 4.5.3 --- Comparison between Celsior and Perfadex solutions on EDHF-mediated function --- p.66 / Chapter 4.5.4 --- Clinical implications --- p.67 / Chapter Chapter 5. --- Exploration of the Nature of EDHF - the Effect of H2O2 on the Membrane Potential in the Rat Small Mesenteric Arteries --- p.73 / Chapter Chapter 6. --- General Discussion --- p.75 / Chapter 6.1 --- EDHF-mediated endothelial function in porcine coronary and pulmonary circulation --- p.75 / Chapter 6.1.1 --- Role of EDHF in the regulation of porcine coronary arterial tone --- p.75 / Chapter 6.1.2 --- Role of EDHF in the regulation of porcine pulmonary arterial tone --- p.76 / Chapter 6.2 --- Alteration of EDHF-mediated endothelial functions after exposure to organ preservation solutions --- p.77 / Chapter 6.2.1 --- Effects of hyperkalemic solution on EDHF-mediated endothelial function in coronary and pulmonary circulation --- p.78 / Chapter 6.2.2 --- Effects of low-potassium-based preservation solution on EDHF-mediated endothelial function in pulmonary circulation --- p.79 / Chapter 6.2.3 --- Comparison between hyperkalemic solution and low-potassium-based preservation solution on EDHF-mediated endothelial function --- p.80 / Chapter 6.2.4 --- Effects of other component of organ preservation solutions on EDHF-mediated endothelial function --- p.81 / Chapter 6.3 --- Clinical implications --- p.82 / Chapter 6.4 --- The effect of H202 on the membrane potential in rat small mesenteric arteries --- p.83 / Chapter 6.5 --- Limitation of the study --- p.84 / Chapter 6.6 --- Future investigations --- p.85 / Chapter 6.7 --- Conclusions --- p.85 / References --- p.87