Kattaya-Annappa-Seema. / Thesis submitted in: December 2006. / "2+" and "+" in the title are superscripts. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 162-188). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.viii / Abstracts published based on work in this thesis --- p.ix / Table of contents --- p.x / Chapter Chapter 1: --- Introduction / Chapter 1.1 --- Pulmonary hypertension / Chapter 1.1.1 --- Pulmonary circulation and its functions --- p.1 / Chapter 1.1.2 --- Pulmonary vascular diseases and symptoms --- p.3 / Chapter 1.2 --- Muscarinic Receptor functions --- p.5 / Chapter 1.3 --- Acetylcholine (ACh) and its function --- p.7 / Chapter 1.4 --- ACh receptors in pulmonary vascular bed --- p.11 / Chapter 1.5 --- Potassium channel classification and functions --- p.12 / Chapter 1.5.1 --- "Importance of High-conductance, Ca2+ activated potassium channel (BKca) in vascular smooth muscle functions" --- p.15 / Chapter 1.5.2 --- Modulation of BKca channel by various cations --- p.18 / Chapter 1.6 --- Calcium signaling and homeostasis --- p.20 / Chapter 1.7 --- Role of sodium in hypertension --- p.22 / Chapter 1.8 --- Na+-H+ exchanger (NHE) functions --- p.25 / Chapter 1.9 --- Na+-Ca2+ exchanger (NCX) in vascular smooth muscle cells --- p.29 / Chapter 1.10 --- Spontaneously hypertensive rat (SHR) / Chapter 1.10.1 --- Hypertension in SHR --- p.32 / Chapter 1.10.2 --- BKca in smooth muscle vasculature of SHR --- p.33 / OBJECTIVES OF THE STUDY --- p.34 / Chapter Chapter 2: --- Material and methods / Chapter 2.1 --- Material / Chapter 2.1.1 --- Solutions and Drugs --- p.35 / Chapter 2.1.2 --- Chemicals and Enzymes --- p.39 / Chapter 2.2 --- Methods / Chapter 2.2.1 --- Isolation of single pulmonary arterial smooth muscle cells --- p.40 / Chapter 2.2.2 --- Electrophysiological measurement --- p.42 / Chapter 2.2.3 --- Data analysis --- p.44 / Chapter Chapter 3: --- Receptor-mediated activation of BKca Channel / Chapter 3.1 --- BKCa activation by ACh/ Carbachol (CCh) --- p.45 / Chapter 3.2 --- Role of extracellular sodium ([Na+]o）on BKca activation --- p.49 / Chapter 3.3 --- Receptor-mediated activation of BKca in a [Na+]o-containing solution --- p.51 / Chapter 3.4 --- Receptor-mediated activation of BKca in a [Na+]o-free solution --- p.55 / Chapter Chapter 4: --- Non-receptor mediated activation of BKCa Channel / Chapter 4.1 --- Effect of different concentrations of sodium nitroprusside (SNP) on BKCa activation --- p.60 / Chapter 4.2 --- Effect of SNP on BKca activation in a [Na+]o-containing and [Na+]o-free solutions --- p.62 / Chapter Chapter 5: --- Role of NHE in modulating activation of BKCa Channel / Chapter 5.1 --- Effect of Monensin on BKca activation / Chapter 5.1.1 --- Effect of monensin on CCh-mediated activation of BKca in a [Na+]o-containing solution --- p.70 / Chapter 5.1.2 --- Effect of monensin on CCh-mediated activation of BKca in a [Na+]o-free solution --- p.74 / Chapter 5.1.3 --- Effect of monensin on SNP- mediated activation of BKca in [Na+]o-containing and [Na+]o-free solutions --- p.78 / Chapter 5.2 --- Effect of 5-(N-ethyl-N-isopropyI) amiloride (EIPA) on BKCa activation / Chapter 5.2.1 --- Effect of EIPA on CCh-mediated activation of BKca in a [Na+]o-containing solution --- p.85 / Chapter 5.2.2 --- Effect of EIPA on CCh-mediated activation of BKca in a [Na+]。-free solution --- p.89 / Chapter 5.2.3 --- Effect of EIPA on SNP-mediated activation of BKCa in [Na+]o-containing and [Na+]o-free solutions --- p.93 / Chapter Chapter 6: --- Role of NCX in modulating activation of BKCa Channel / Chapter 6.1 --- Effect of KB-R7943 on CCh-mediated activation of BKCa in a [Na+]o-containing solution --- p.100 / Chapter 6.2 --- Effect of KB-R7943 on CCh-mediated activation of BKCa in a [Na+]o-free solution --- p.104 / Chapter 6.3 --- Effect of KB-R7943 on SNP-mediated activation of BKca in [Na+]o-containing and [Na+]o-free solutions --- p.109 / Chapter Chapter 7: --- Effect of intracellular sodium ([Na+]i) on BKCa channel activation / Chapter 7.1 --- Effect of CCh on BKCa channel activation with elevated [Na+]i pipette solution --- p.117 / Chapter 7.2 --- Effect of SNP on BKca channel activation with elevated [Na+]j pipette solution --- p.130 / Chapter Chapter 8: --- Discussion / Chapter 8.1 --- Modulatory effect of ACh and SNP --- p.138 / Chapter 8.2 --- Role of ion exchangers: NHE and NCX in modulating BKca channel function --- p.144 / Chapter 8.3 --- Modulatory effect of elevated [Na+]i on BKca activation --- p.153 / CONCLUSION --- p.161 / References --- p.162