A method was developed which allowed for more consistent liposome quality, reducing the standard error of initial rates for Zn2+ diffusion by 30%. Introducing low concentration of platelet-activating-factor (PAF), 1-palmitoyl-L-lyso-3-phosphocholine (Lyso-PC), or 1-oleoyl-2-acetyl-sn-glycero-3-phosphocholine (Acyl-PAF) to 1palmitoyl.-2-oleoyl-sn-glycero-3-phosphocholine (POPC) liposomes did not have any noticeable impact on zinc diffusion. Since diffusion is dependent on membrane composition and properties, it can be concluded that PAF, Lyso-PC, and Acyl-PAF did not alter POPC liposome properties significantly. Zn2+ and Cd2+ kinetic experiments showed binding to the liposome surface prior to diffusion and a mutual diffusing species, the monohydroxo complex. Although Mn 2+ did not diffuse to any measurable extent, binding to the liposome surface was also observed. Cue+ and Pb 2+ on the other hand follow a more complex diffusion mechanism, which requires further investigation. / Department of Chemistry

Chau Shuk Ling. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 103-115). / Abstracts in English and Chinese. / DECLARATION --- p.i / ACKNOWLEDGEMENT --- p.ii / ABBREVIATIONS --- p.iii / ABSTRACT IN ENGLISH --- p.v / ABSTRACT IN CHINESE --- p.viii / TABLE OF CONTENTS --- p.xi / Chapter CHAPTER I - --- INTRODUCTION / Chapter 1.1 --- Fluid Transport in Human Colon --- p.1 / Chapter 1.2 --- C1' Secretion across the Colonic Epithelium --- p.2 / Chapter 1.3 --- Properties of T84 Cells --- p.7 / Chapter 1.4 --- General Introduction on Extracellular Calcium Sensing Receptor (CaSR) --- p.8 / Chapter 1.5 --- Molecular Structure of CaSR --- p.9 / Chapter 1.6 --- CaSR-mediated Intracellular Signaling --- p.13 / Chapter 1.7 --- Agonists of CaSR --- p.16 / Chapter 1.8 --- Functions of CaSR --- p.18 / Chapter 1.8.1 --- Homeostatic Functions of CaSR --- p.18 / Chapter 1.8.2 --- Non-Homeostatic Functions of CaSR --- p.18 / Chapter 1.9 --- Molecular and Functional Study of CaSR Expressed in Colon --- p.19 / Chapter 1.10 --- Objectives of the Present Study --- p.21 / Chapter CHAPTER II - --- MATERIALS AND METHODS / Chapter 2.1 --- Solutions and Drugs --- p.22 / Chapter 2.2 --- Cell Culture --- p.23 / Chapter 2.3 --- Western Blot --- p.26 / Chapter 2.4 --- Simultaneous Measurement of Short-Circuit Current (Isc) and Intracellular Calcium Concentration ([Ca2+]i) --- p.27 / Chapter 2.4.1 --- Measurement of Isc and Transepithelial Resistance with Ussing Chamber --- p.27 / Chapter 2.4.2 --- Simultaneous Measurement of Isc and [Ca2+]i --- p.29 / Chapter 2.5 --- Measurement of Isc with Conventional Ussing Chamber --- p.32 / Chapter 2.6 --- Measurement of Intracellular cAMP Accumulation with Enzyme-Linked Immunosorbent Assay --- p.34 / Chapter 2.7 --- Data Analysis --- p.34 / Chapter CHAPTER III - --- RESULTS / Chapter 3.1 --- Expression of CaSR in T84 Cell Monolayers --- p.36 / Chapter 3.2 --- Poly L-arginine Induced an Increase in Isc --- p.38 / Chapter 3.2.1 --- Simultaneous Measurement of Isc and [Ca2+ ]i in Response to Poly L-arginine --- p.38 / Chapter 3.2.2 --- Interaction Between Poly L-arginine and Forskolin --- p.50 / Chapter 3.2.3 --- Ionic Mechanism of Isc Stimulated by Poly L-arginine --- p.58 / Chapter 3.2.3.1 --- Involvement of C1- in Isc Stimulated by Poly L-arginine --- p.58 / Chapter 3.2.3.2 --- Involvement of Basolateral K+ Channels in Isc Stimulated by Poly L-arginine --- p.61 / Chapter 3.2.4 --- Signaling Pathways Underlying the Isc Response to Poly L-arginine --- p.73 / Chapter CHAPTER IV - --- DISSCUSION / Chapter 4.1 --- Presence of CaSR in T84 Cell Monolayers --- p.78 / Chapter 4.2 --- Simultaneous Measurement of Isc and [Ca2+ ]i upon Application of Poly L-arginine --- p.82 / Chapter 4.3 --- Ionic Mechanism Underlying the Increase in Isc Stimulated by Poly L-arginine --- p.87 / Chapter 4.4 --- Signaling Pathway Underlying the Action of Poly L-arginine --- p.93 / Chapter 4.5 --- Does CaSR Mediate Poly L-arginine-evoked C1- Secretion across T84 Cell Monolayers? --- p.96 / Chapter 4.6 --- Future Study --- p.101 / REFERENCES --- p.103