Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 210-219).

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xviii, 257 p.; also includes graphics (some col.) Includes bibliographical references (p. 245-257).

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 60-71). Also available in electronic version. Access restricted to campus users.

Chan Ho Yu, Richard. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 115-122). / Abstracts in English and Chinese. / Declaration --- p.i / Acknowledgements --- p.ii / Abstract --- p.iii / 摘要 --- p.v / Table of Contents --- p.vii / Chapter Chapter 1: --- Introduction --- p.1 / Chapter 1.1 --- Potassium Channels --- p.1 / Chapter 1.1.1 --- Potassium Ions --- p.1 / Chapter 1.1.2 --- Potassium Channels --- p.1 / Chapter 1.1.3 --- Structure of K Channels --- p.2 / Chapter 1.1.4 --- Classification ofK Channels --- p.3 / Chapter 1.1.5 --- Mechanisms Contributed to K Channel Functions and Diversity --- p.5 / Chapter 1.1.5.1 --- RNA Editing --- p.5 / Chapter 1.1.5.2 --- Alternative Splicing --- p.6 / Chapter 1.1.5.3 --- Heteromultimeric Assembly of Principal Subunits --- p.6 / Chapter 1.1.5.4 --- Auxiliary Subunits --- p.7 / Chapter 1.1.5.5 --- Posttranslational Modifications --- p.7 / Chapter 1.2 --- Voltage-gated Potassium (Kv) Channels --- p.9 / Chapter 1.2.1 --- Diversity of Kv Channel Structure --- p.9 / Chapter 1.2.2 --- Early Origin of the Kv Family --- p.10 / Chapter 1.2.3 --- Structural Diversity of Kv Channels in Drosophila --- p.11 / Chapter 1.2.4 --- Structural Diversity of Kv Channels in Mammals --- p.11 / Chapter 1.2.5 --- Phylogenetic Tree of Kv Family --- p.13 / Chapter 1.2.6 --- Tissue Expression of Kv Channels --- p.13 / Chapter 1.2.7 --- "Three Main Functions of Kv Channels as Signaling Proteins: Ion Permeation, Gating and Sensing" --- p.16 / Chapter 1.2.7.1 --- Ion Permeation --- p.16 / Chapter 1.2.7.2 --- Gating --- p.18 / Chapter 1.2.7.2.1 --- Gating at the S6 Bundle Crossing --- p.18 / Chapter 1.2.7.2.2 --- Ball-and-Chain Gating --- p.19 / Chapter 1.2.7.2.3 --- Gating at the Selectivity Filter --- p.19 / Chapter 1.2.7.3 --- Sensing Mechanisms --- p.20 / Chapter 1.2.7.3.l --- Voltage Sensor --- p.20 / Chapter 1.2.7.3.2 --- Gating Sensors for Ligands --- p.21 / Chapter 1.3 --- KCNA10 --- p.22 / Chapter 1.3.1 --- "Rabbit Homologue of KCNA10, Kcnl" --- p.22 / Chapter 1.3.2 --- Genomic Localization of Human KCNA10 --- p.23 / Chapter 1.3.3 --- Human Gene for KCNA10 --- p.23 / Chapter 1.3.4 --- Basic Kinetic and Pharmacological Properties of KCNA10 --- p.25 / Chapter 1.3.5 --- "Regulation of KCNAlO by KCNA4B, a β -subunit" --- p.27 / Chapter 1.4 --- Aim of the Present Study --- p.30 / Chapter Chapter2: --- Materials and Methods --- p.31 / Chapter 2.1 --- Molecular Sub-Cloning ofKCNAlO --- p.31 / Chapter 2.1.1 --- Polymerase Chain Reaction (PCR) ofKCNA10 Fragment from KCNA Clone --- p.10 / Chapter 2.1.2 --- Separation and Purification of PCR Products --- p.32 / Chapter 2.1.2.1 --- Separation --- p.32 / Chapter 2.1.2.2 --- Purification --- p.33 / Chapter 2.1.3 --- Polishing the Purified PCR Products --- p.33 / Chapter 2.1.4 --- Ligation of PCR Products and pPCR-Script Amp SK(+) Cloning Vector --- p.34 / Chapter 2.1.5 --- Transformation --- p.34 / Chapter 2.1.6 --- Preparing Glycerol Stocks Containing the Bacterial Clones --- p.35 / Chapter 2.1.7 --- Plasmid DNA Preparation --- p.35 / Chapter 2.1.8 --- Clones Confirmation --- p.36 / Chapter 2.1.8.1 --- Restriction Enzyme Digestion --- p.36 / Chapter 2.1.8.2 --- Automatic Sequencing --- p.37 / Chapter 2.2 --- In situ Hybridization --- p.39 / Chapter 2.2.1 --- Probe Preparation --- p.39 / Chapter 2.2.1.1 --- Antisense KCNA10 RNA Probe --- p.39 / Chapter 2.2.1.2 --- Sense KCNA10 RNA Probe (Control Probe) --- p.40 / Chapter 2.2.2 --- Testing of DIG-Labeled RNA Probes --- p.43 / Chapter 2.2.3 --- Paraffin Sections Preparation --- p.43 / Chapter 2.2.4 --- In situ Hybridization: Pretreatment --- p.44 / Chapter 2.2.5 --- "Pre-hybridization, Hybridization and Post-hybridization" --- p.45 / Chapter 2.2.5.1 --- Pre-hybridization --- p.45 / Chapter 2.2.5.2 --- Hybridization --- p.45 / Chapter 2.2.5.3 --- Post-hybridization --- p.46 / Chapter 2.2.6 --- Colourimetnc Detection of Human KCNA10 --- p.46 / Chapter 2.3 --- Cell Culture --- p.47 / Chapter 2.3.1 --- Human Kidney Proximal Epithelial Cell Line (OK) --- p.47 / Chapter 2.3.2 --- Mouse Micro-vessel Endothelial Cell Line (H5V) --- p.48 / Chapter 2.3.3 --- Mouse Neuroblastoma Cell Line (NG108-15) --- p.48 / Chapter 2.3.4 --- Human Bladder Epithelial Cell Line (ECV304) --- p.48 / Chapter 2.3.5 --- Human T Cell Leukemia Cell Line (Jurkat) --- p.49 / Chapter 2.4 --- Total RNA Extraction --- p.49 / Chapter 2.5 --- Reverse Transcription from Cell Line --- p.51 / Chapter 2.6 --- Polymerase Chain Reaction (PCR) ofKCNAl 0 Fragment from Frist Strand cDNA --- p.51 / Chapter 2.7 --- Northern Hybridization --- p.52 / Chapter 2.7.1 --- Probe Preparation --- p.52 / Chapter 2.7.2 --- Separating RNA on an Agarose Gel --- p.52 / Chapter 2.7.3 --- RNA Transfer and Fixation --- p.52 / Chapter 2.7.4 --- Hybridization --- p.54 / Chapter 2.7.5 --- Post-hybridization --- p.54 / Chapter 2.7.6 --- Chemiluminescent Detection --- p.55 / Chapter 2.8 --- Intracellular Free Calcium Ion ([Ca2+］i) Measurement by Confocal Imaging System --- p.56 / Chapter 2.8.1 --- Bathing Solutions --- p.56 / Chapter 2.8.2 --- Preparation of Cells for [Ca2+]i Measurement --- p.56 / Chapter 2.8.3 --- Confocal Imaging System --- p.57 / Chapter 2.8.3.1 --- Fluo-3/AM Dye Loading --- p.57 / Chapter 2.8.3.2 --- [Ca2+]i Measurement --- p.57 / Chapter Chapter3: --- Results --- p.59 / Chapter 3.1 --- Phylogenetic Tree Reconstruction ofKCNAl0 --- p.59 / Chapter 3.2 --- Hydropathy Analysis ofKCNAl0 --- p.60 / Chapter 3.3 --- Molecular Sub-Cloning ofKCNAl0 --- p.61 / Chapter 3.3.1 --- Polymerase Chain Reaction (PCR) ofKCNAl0 Fragment from KCNA10 Clone --- p.61 / Chapter 3.3.2 --- Clones Confirmation --- p.63 / Chapter 3.4 --- In situ Hybridization Analysis ofKCNAl0 mRNAExpression --- p.65 / Chapter 3.4.1 --- Expression ofKCNAl0 in Human Kidney (Nephron) --- p.66 / Chapter 3.4.2 --- Expression ofKCNAl0 in Human Cerebral Artery --- p.69 / Chapter 3.4.3 --- Expression ofKCNAl0 in Human Cerebellum --- p.71 / Chapter 3.4.4 --- Expression ofKCNAl0 in Human Hippocampus --- p.73 / Chapter 3.4.5 --- Expression ofKCNAl0 in Human Occipital Cortex --- p.75 / Chapter 3.4.6 --- Expression ofKCNAl0 in Human Esophagus --- p.77 / Chapter 3.4.7 --- Expression ofKCNAl0 in Human Lung --- p.79 / Chapter 3.4.8 --- Expression ofKCNAl0 in Human Thyroid Glands --- p.81 / Chapter 3.4.9 --- Expression ofKCNAl0 in Human Adrenal Glands --- p.83 / Chapter 3.4.10 --- Expression ofKCNAl0 in Human Spleen --- p.86 / Chapter 3.5 --- RT-PCR ofKCNAl0 Fragment from Different Tissues --- p.88 / Chapter 3.6 --- Northern Blot Analysis of KCNA10 in Different Tissues --- p.90 / Chapter 3.7 --- Effects of Blocking KCNA10 on Ca2+ influx in Human Renal Proximal Tubule Epithelial Cells --- p.91 / Chapter Chapter4: --- Discussion --- p.97 / Chapter 4.1 --- Phylogency ofKCNAlO --- p.97 / Chapter 4.2 --- Hydropathy Plot for KCNA10 --- p.97 / Chapter 4.3 --- Expression ofKCNAl0 --- p.98 / Chapter 4.3.1 --- In situ Hybridization --- p.98 / Chapter 4.3.2 --- RT-PCR & Northern Blot Analysis --- p.99 / Chapter 4.4 --- Functional Implication of KCNA10 Expression in Different Human Tissues --- p.100 / Chapter 4.4.1 --- Unique Functional Properties ofKCNAlO --- p.100 / Chapter 4.4.2 --- Role ofKCNAlO in Renal Proximal Tubule --- p.101 / Chapter 4.4.2.1 --- Functions ofK+ Channels in Kidney --- p.101 / Chapter 4.4.2.2 --- The Function ofKCNAlO --- p.104 / Chapter 4.4.3 --- Role ofKCNAl0 in Blood Vessels --- p.106 / Chapter 4.4.3.1 --- Endothelial Cells --- p.106 / Chapter 4.4.3.2 --- Smooth Muscle Cells --- p.108 / Chapter 4.4.4 --- Role ofKCNA10 in CNS --- p.109 / Chapter 4.4.5 --- Role ofKCNAl0 in Secretory Cells --- p.111 / Chapter 4.4.6 --- Role ofKCNAl0 in Lung --- p.112 / Chapter 4.5 --- Conclusion --- p.114 / Chapter Chapter5： --- Reference --- p.115

Thesis (Ph. D.)--University of Wyoming, 2006. / Title from PDF title page (viewed on Nov. 15, 2007). Includes bibliographical references.

This thesis is mainly concerned with the study of the role of cGMP in regulating contractility in the heart and blood vessels. A novel cGMP lowering agent, LY83583 (6-anilino-5,8-quinolinedione), was employed as a tool to determine the involvement of cGMP in mediating pharmacological and biological responses in the tissues being examined. In the first study, the role of cGMP in atriopeptin II-induced vascular relaxation was investigated. Atriopeptin II is believed to produce its vasorelaxant effect by virtue of its ability to elevate cGMP. However, the ability of the guanylate cyclase inhibitor, methylene blue, to inhibit the atriopeptin II-induced vasorelaxation has not been conclusively demonstrated. In the present study, LY83583 was found to partially prevent the rise in cGMP level caused by atriopeptin II but was without effect on the extent of the relaxation. This lack of correlation between cGMP elevation and relaxation may indicate either functional compartmentalization of the cyclic nucleotide or the existence of a cGMP-independent pathway for relaxation. Alternatively, the attenuated cGMP level may still be sufficient to elicit full relaxation. The inability of atriopeptin II to relax KC1-contracted bovine coronary arteries agrees with other reports in the literature and may indicate that the drug is less effective in antagonizing vascular responses associated with a marked degree of cell membrane depolarization. In the second study, the role of cGMP in mediating the endothelium-dependent inhibition of contractile responses of vascular tissue to alpha adrenoceptor stimulation was examined. There are reports in the literature that EDRF released from the endothelium elevates cGMP and depresses the response of the vessels to vasoconstrictors such as clonidine and norepinephrine. In the present study, LY83583 was used to examine the role of cGMP in mediating this effect. The treatment with LY83583 significantly lowered basal levels of cGMP and markedly enhanced the contractile response of endothelium-containing rat arteries to clonidine and norepinephrine. cGMP measurements indicate that clonidine did not elevate cGMP levels; hence the drug is unlikely to stimulate EDRF release. On the other hand, the depressant action of LY83583 on basal cGMP levels supports the hypothesis that inhibition of contractile responses may be a result of spontaneous release of EDRF, which results in tonic elevation of cGMP. The ability of 8-bromo-cGMP to reverse LY83583-induced enhancement of contractile responses to clonidine and norepinephrine further supports the involvement of cGMP in EDRF-induced vascular relaxation. In the final study, the role of cGMP in regulating cardiac contractility of amphibian ventricles was examined. The importance of cGMP in controlling mammalian cardiac function is controversial. However, a remarkable correlation between cGMP and contractile force has been reported in hypodynamic frog ventricles, and cAMP and cGMP were reported to act in a reciprocal fashion to regulate contractility. The present investigation attempted to verify whether such a relationship actually exists in the frog ventricles. Carbachol elicited a dose-dependent reduction in contractility without altering cGMP levels. On the contrary, sodium nitroprusside (100µM) did not reduce cardiac contractility despite a significant elevation of cGMP. At 1mM sodium nitroprusside, a huge elevation of cGMP and a small reduction in contractile tension were observed. Qualitatively similar results were obtained with a degraded sample of sodium nitroprusside. cAMP/cGMP ratios were not correlated with contractility. Hence, these findings were inconsistent with those found in earlier studies on hypodynamic frog hearts and do not support the proposed role of cGMP as a second messenger. The disparate findings may be caused by differences in experimental design. Alternatively, functional compartmentalization of cGMP (in the case of sodium nitroprusside) and the involvement of other cGMP-independent pathways (in the case of carbachol) cannot be ruled out. All these findings suggest that cGMP may play a more crucial role in regulating vascular than cardiac contractility. / Pharmaceutical Sciences, Faculty of / Graduate

No description available.

Thesis (Ph. D.)--University of Missouri--Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 95-113). Also available on the Internet.

Thesis (PhD)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Ischaemic preconditioning (PC) is the phenomenon whereby a short episode of coronary occlusion followed by reperfusion protects the myocardium against a subsequent period of prolonged (also called index or sustained) ischaemia. Even though the exact mechanism of PC remains to be established, it implies that the heart has an endogenous protective mechanism against ischaemia which, if identified, may have important clinical implications. The importance of establishing the mechanism of PC lies in the potential to convert this biological phenomenon into a therapeutic modality to be used clinically. If mediated by certain components of a signal transduction pathway, such a goal will be achievable. Several triggers and signal transduction pathways have been implicated in the mechanism of protection induced by PC: for example, receptor-dependent endogenous triggers (such as adenosine and opioids) and receptor-independent endogenous triggers (such as free radicals and calcium). However, the involvement of both the ~-adrenergic signalling pathway as well as nitric oxide (NO) in PC has not been defined. It has been suggested that all triggers are linked to a common final pathway, for example, activation of protein kinase C (PKC) and/or the mitogen-activated kinases (MAPKs), in particular p38 MAPK. However, the role of the latter is still controversial. The aim of this study was to: (A) characterize changes in the cyclic nucleotides, cAMP and cGMP, and p38 MAPK occurring during the entire experimental procedure in an attempt to gain insights into the possible mechanisms involved in ischaemie PC (Chapter 3); (8) establish the significance of the changes observed in cAMP and cGMP by pharmacological manipulation of their respective pathways (Chapters 4 and 5); (C) establish the role of p38 MAPK in ischaemie PC: trigger or mediator involvement (Chapter 6). Isolated perfused working rat hearts were preconditioned by 3 x 5 min global ischaemia, interspersed by 5 min reperfusion, followed by 25 min global ischaemia and 30 min reperfusion. Functional recovery during reperfusion was used as end-point. Hearts were freeze-clamped at different times during the PC protocol, sustained ischaemia, as well as during reperfusion. Tissue cyclic nucleotides (cAMP and cGMP), cyclic nucleotide phosphodiesterase (cAMP- and cGMP-PDE) activities, adenylyl cyclase and protein kinase A activities and p-adrenergic receptor characteristics were determined. p38 MAPK activation was also assessed by Western blotting, using dual phospho-p38 MAPK (Thr180ITyr182) antibody as well as activating transcription factor 2 (ATF2) activation. In addition, to evaluate the role of p38 MAPK in PC protection, the effect of inhibition of p38 MAPK activation, by 8B203580, was determined in adult isolated rat cardiomyocytes as well as in isolated perfused rat hearts. Based on the results obtained, it is proposed that during a multi-cycle ischaemie PC protocol triggers (presumably endogenous catecholamines and NO) are released which induce cyclic changes in cyclic nucleotides, cAMP and cGMP. Both these cyclic nucleotides transiently activate the downstream stress kinase, p38 MAPK, which may trigger further downstream adaptive processes. Furthermore, the sustained ischaemic period of PC hearts was characterized by attenuated cAMP and elevated cGMP levels, as well as attenuated activation of p38 MAPK, which was associated with cardioprotection. In addition, pharmacological attenuation of p38 MAPK activation during sustained ischaemia led to functional recovery. It is concluded that the cardioprotection of PC is due to attenuation of ischaemia-induced p38 MAPK activation. Pharmacological manipulation of this kinase should be considered as a therapeutic modality in the future. / AFRIKAANSE OPSOMMING: Isgemiese prekondisionering (PK) verwys na die verskynsel waardeur 'n kort, verbygaande episode van isgemie gevolg deur herperfusie, die miokardium teen 'n daaropvolgende langdurige periode van isgemie beskerm. Die presiese meganisme van beskerming van PK moet nog opgeklaar word, maar dit impliseer dat die hart oor 'n endogene beskermingsmeganisme beskik wat, indien geïdentifiseer, belangrike kliniese implikasies mag hê. Die belang van opklaring van die meganisme van PK lê daarin dat 'n biologiese verskynsel in 'n terapeutiese modaliteit vir kliniese gebruik, omgeskakel kan word. Sou dit deur bepaalde komponente van 'n seintransduksiepad gemedieër word, is so 'n doel bereikbaar. Verskeie stimuli en seintransduksiepaaie is in PK betrokke: byvoorbeeld, reseptorafhanklike endogene stimuli (soos adenosien en opioïde), asook reseptor-onafhanklike endogene stimuli (soos vrye radikale en kalsium). Die betrokkenheid van die padrenerge seintransduksiepad asook stikstofoksied (NO) in PK egter nog nie behoorlik evalueer nie. Dit is voorgestel dat alle stimuli op 'n finale algemene pad uitloop, soos byvoorbeeld die aktivering van protein kinase C (PKC) en/of die mitogeen-geaktiveerde kinases (MAPKs), spesifiek die p38 MAPKs. Laasgenoemde se rol in PK is steeds kontroversieël. Die doel van die studie was dus: (A) karakterisering van die veranderinge in die sikliese nukleotiede, cAMP en cGMP, en p38 MAPK wat tydens die hele eksperimentele prosedure plaasvind, in 'n poging om meer insig te verkry aangaande moontlike meganismes betrokke in isgemiese PK (Hoofstuk 3); (8) bepaling van die belang van die waargenome veranderinge in cAMP en cGMP deur hulonderskeie paaie farmakologies te manipuleer (Hoofstukke 4 en 5); (C) bepaling van die rol van p38 MAPK in PK: betrokkenheid as stimulus of mediator (Hoofstuk 6). Geïsoleerde, geperfuseerde werkende rotharte is geprekondisioneer deur blootstelling aan 3 x 5 min globale isgemie, afgewissel met 5 min herperfusie, gevolg deur 25 min globale isgemie en 30 min herperfusie. Funksionele herstel tydens herperfusie is as eindpunt gebruik. Harte is op verskillende tye tydens die PK protokol, volgehoue isgemie, asook herperfusie gevriesklamp. Weefsel sikliese nukleotiede (cAMP en cGMP), die aktiwiteit van sikliese nukleotied fosfodiesterases (cAMP- en cGMP-PDE), adeniel siklase en protein kinase A (PKA) asook die eienskappe van die p-adrenerge reseptor is gemeet. p38 MAPK aktivering is met Westerse oordragtegnieke bepaal, deur van dubbel gefosforileerde p38 MAPK (Thr180fTyr182) antiliggame asook geaktiveerde transkripsie faktor 2 (ATF2) gebruik te maak. Die rol van p38 MAPK in PK beskerming is evalueer deur die effek van inhibisie van p38 MAPK aktivering met SB 203580, in volwasse geïsoleerde rot kardiomiosiete asook in geïsoleerde geperfuseerde rotharte, te bepaal. Na aanleiding van die resultate, is voorgestel dat, tydens 'n multi-siklus isgemie PK protokol, stimuli (moontlik endogene katekolamiene en NO) vrygestel word wat die sikliese veranderinge in sikliese nukleotiede, cAMP en cGMP, veroorsaak. Beide hierdie sikliese nukleotiede aktiveer die distale stres kinase, p38 MAPK, op 'n betekenisvolle, maar verbygaande manier. Hierdie kinase mag verdere distale aanpassingsprosesse stimuleer. Die volgehoue isgemiese periode van PK harte is gekenmerk deur verminderde cAMP en verhoogde cGMP vlakke, asook verminderde aktivering van p38 MAPK. Hierdie veranderinge is met beskerming van die hart teen isgemie geassosieer. Daarbenewens, farmakologiese vermindering van p38 MAPK aktivering tydens volgehoue isgemie het tot verbeterde funksionele herstel gelei. Die gevolgtrekking is gemaak dat die beskermende effek van PK die gevolg is van verminderde aktivering van isgemies-geïnduseerde p38 MAPK. Farmakologiese manipulasie van hierdie kinase moet in die toekoms as terapeutiese modaliteit oorweeg word.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 134-144). Also available on the Internet.