Effects of phytosterols and phytosterol oxidation products on the vasculature.

Yang, Chao.Thesis (M.Phil.)--Chinese University of Hong Kong, 2011.Includes bibliographical references (leaves 137-146).Abstracts in English and Chinese.Thesis Committee --- p.iAcknowledgements --- p.iiContents --- p.iiiDeclaration --- p.viiAbstract --- p.viii摘要 --- p.xiAbbreviations --- p.xiiiChapter CHAPTER ONE: --- INTRODUCTIONChapter 1.1 --- Occurrence and Structure of Phytosterols in Plants --- p.P.1Chapter 1.2 --- Biological Effects of PhytosterolsChapter 1.2.1 --- Cholesterol-lowering Effect of Phytosterols --- p.P.3Chapter 1.2.2 --- Anti-cancer Effect of Phytosterols --- p.P.5Chapter 1.2.3 --- Anti-proliferative Effect of Phytosterols --- p.P.5Chapter 1.3 --- Intake and Absorption of Phytosterols in Human Beings --- p.P.6Chapter 1.4 --- Occurrence and Physiological Levels of Phytosterol Oxidation Products (POPs)Chapter 1.4.1 --- Occurrence of POPs --- p.P.8Chapter 1.4.2 --- Physiological Levels of POPs --- p.P.8Chapter 1.5 --- Endothelium and the Vascular ToneChapter 1.5.1 --- Role of Endothelium in the Control of Vascular Tone --- p.P.11Chapter 1.5.2 --- "Endothelial Dysfunction, Cholesterol Oxidation Products (COPs) and Phytosterol Oxidation Products (POPs)" --- p.P.12Chapter 1.6 --- Calcium Homeostasis in the Vascular Smooth Muscle Cells (VSMCs)Chapter 1.6.1 --- Modes of Ca2+ Entry in VSMCs --- p.P.15Chapter 1.6.2 --- Modes of Ca2+ Efflux in VSMCs --- p.P.18Chapter 1.7 --- Objectives of the Study --- p.P.19Chapter CHAPTER TWO: --- β-SITOSTEROL OXIDATION PRODUCTS ATTENUATE VASORELAXATION BY INCREASING REACTIVE OXYGEN SPECIES AND CYCLOOXYGENASE-2Chapter 2.1 --- Introduction --- p.P.21Chapter 2.2 --- Materials and MethodsChapter 2.2.1 --- Preparation of SOPs --- p.P.24Chapter 2.2.2 --- Gas Chromatography -mass Spectrometry (GC-MS) Identification of SOPs --- p.P.24Chapter 2.2.3 --- Analysis of SOPs --- p.P.25Chapter 2.2.4 --- Vessel Preparation --- p.P.25Chapter 2.2.5 --- Isometric Force Measurement --- p.P.26Chapter 2.2.6 --- Western Blotting --- p.P.27Chapter 2.2.7 --- Primary Culture of Rat Aortic Endothelial Cell --- p.P.28Chapter 2.2.8 --- Measurement of SOPs-induced Intracellular Oxidative Stress --- p.P.29Chapter 2.2.9 --- Drugs --- p.P.30Chapter 2.2.10 --- Data Analysis --- p.P.30Chapter 2.3 --- ResultsChapter 2.3.1 --- GC-MS Identification of SOPs --- p.P.32Chapter 2.3.2 --- Analysis of SOPs --- p.P.34Chapter 2.3.3 --- SOPs But Not β-Sitosterol Impaired ACh- and A23187-induced relaxations --- p.P.36Chapter 2.3.4 --- Inhibition of COX Pathway Reversed SOPs-induced Impairment in Relaxation --- p.P.39Chapter 2.3.5 --- SOPs Elevated Endothelial COX-2 Expression --- p.P.42Chapter 2.3.6 --- SOPs Increased COX-2 Expression via An Oxidative Stress-sensitive Pathway --- p.P.45Chapter 2.4 --- Discussion --- p.P.52Chapter 2.5 --- Conclusion --- p.P.56Chapter CHAPTER THREE: --- β-SITOSTEROL OXIDATION PRODUCTS POSSESS POTENTIAL VOCC BLOCKING EFFECT IN VSMCsChapter 3.1 --- IntroductionChapter 3.1.1 --- 2+ Modes of Ca Entry and Efflux in Vascular Smooth Muscle Cells (VSMCs) --- p.P.57Chapter 3.1.2 --- Effect of Cholesterol and COPs on VSMCs --- p.P.57Chapter 3.2 --- Methodology and MaterialsChapter 3.2.1 --- Vessel Preparation --- p.P.59Chapter 3.2.2 --- Isometric Force Measurement iv --- p.P.59Chapter 3.2.3 --- Drugs --- p.P.60Chapter 3.2.4 --- Data Analysis --- p.P.61Chapter 3.3 --- ResultsChapter 3.3.1 --- SOPs but not β-Sitosterol Induced Relaxation in 60 mM K+ -preconstricted Endothelium-denuded Aorta --- p.P.62Chapter 3.3.2 --- Both SOPs and β-Sitosterol did not Relax U46619-preconstricted Endothelium-denuded Aorta --- p.P.64Chapter 3.3.3 --- Both SOPs and β-Sitosterol did not Relax PDA -preconstricted Endothelium-denuded Aorta --- p.P.66Chapter 3.3.4 --- SOPs Attenuated 60 mM K+-induced Contraction --- p.P.68Chapter 3.3.5 --- SOPs Attenuated Phenylephrine-induced Contraction --- p.P.70Chapter 3.3.6 --- Effect of SOPs on Concentration-dependent Responses to U46619 --- p.P.72Chapter 3.3.7 --- Preincubation with Bay K 8644 Abolished SOPs-induced Relaxation in 60 mM K+ -preconstricted Rings --- p.P.74Chapter 3.3.8 --- Preincubation with Thapsigargin did not Affect SOPs-induced Relaxation in 60 mM K+ -preconstricted Rings --- p.P.76Chapter 3.3.9 --- Preincubation with Ouabain did not Affect SOPs-induced Relaxation in 60 mM K+ -preconstricted Rings --- p.P.78Chapter 3.3.10 --- Preincubation with Nickel Potentiated SOPs-induced Relaxation in 60 mM K+ -preconstricted Rings --- p.P.80Chapter 3.4 --- Discussion --- p.P.84Chapter 3.5 --- Conclusion and Future Work --- p.P.88Chapter CHAPTER FOUR: --- INVOLEMENT OF NITRIC OXIDE IN THE PROTECTIVE EFFECTS OF PHYTOSTEROLS AGAINST HOMOCYSTEINE-INDUCED IMPAIRMENT OF ENDOTHELIUM-DEPENDENT RELAXATIONS OF RAT AORTAChapter 4.1 --- Introduction --- p.P.89Chapter 4.2 --- Materials and MethodChapter 4.2.1 --- Vessel Preparation --- p.P.93Chapter 4.2.2 --- Isometric Force Measurement --- p.P.93Chapter 4.2.3 --- Western Blotting --- p.P.94Chapter 4.2.4 --- "1,1 -diphenyl-2-picrylhydrazyl (DPPH) Radical Scavenging Capacity" --- p.P.96Chapter 4.2.5 --- Primary Culture of Rat Aortic Endothelial Cells V --- p.P.96Chapter 4.2.6 --- Measurement Intracellular Oxidative Stress --- p.P.97Chapter 4.2.7 --- Nitric Oxide (NO) Measurement --- p.P.97Chapter 4.2.8 --- Drugs --- p.P.98Chapter 4.2.9 --- Data Analysis --- p.P.99Chapter 4.3 --- ResultsChapter 4.3.1 --- Impairment of Endothelium-dependent Relaxation by HC was Reversed by ROS Scavenger --- p.P.100Chapter 4.3.2 --- Brassicasterol Reversed HC-induced Endothelial Dysfunction In a Dose-dependent Manner --- p.P.102Chapter 4.3.3 --- β-Sitosterol and Stigmasterol Reversed HC-induced Endothelial Dysfunction --- p.P.104Chapter 4.3.4 --- Effects of β-Sitosterol Oxidation Products (SOPs) on HC-induced Endothelial Dysfunction --- p.P.106Chapter 4.3.5 --- Effects of Brassicasterol and β-Sitosterol on H2O2-induced Impairment of Endothelium-dependent Relaxation --- p.P.108Chapter 4.3.6 --- Phytosterols did not Directly Scavenge Free Radicals --- p.P.110Chapter 4.3.7 --- "HC and Brassicasterol did not Affect the Expression of SOD-1, SOD-2, eNOS, COX-1 and COX-2 in Aorta" --- p.P.112Chapter 4.3.8 --- HC Increased ROS Production in Primary Rat Aortic Endotelial Cells --- p.P.116Chapter 4.3.9 --- Brassicasterol did not Reverse the ROS Production by HC treatment In the Endothelial Cells --- p.P.120Chapter 4.3.10 --- Effect of L-NAME on Reversing the Effect of Brassicasterol on ACh-induced Relaxation --- p.P.123Chapter 4.3.11 --- Brassicasterol Reversed the Inhibitory Effect of HC on ACh-induced NO Production in Endothelial Cells --- p.P.125Chapter 4.4 --- Discussion --- p.P.128Chapter 4.5 --- Conclusion and Future Work --- p.P.132Chapter CHAPTER FIVE: --- CONCLUSIONS AND FUTURE WORK --- p.P.134Chapter CHAPTER SIX: --- REFERENCES --- p.P.13