published_or_final_version / abstract / Physiology / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Obstetrics and Gynaecology / Master / Master of Philosophy

published_or_final_version / abstract / Zoology / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Zoology / Master / Master of Philosophy

published_or_final_version / Biological Sciences / Master / Master of Philosophy

published_or_final_version / Physiology / Doctoral / Doctor of Philosophy

Thirty-eight female Wistar rats were studied to determine the response of citrate synthase (CS) and glycogen (GLY) to two similar programs of endurance training. Animals were randomly assigned to one of three groups: run-trained (RUN), swim-trained (SWIM) or sedentary control (CON). The treadmill trained animals ran at a speed of 27 m/min. up an eight degree incline. The swim-trained animals swam with 2% of body weight attached to their tails. The duration of the exercise protocols was 2 hours/day, the frequency 5 days/week and the length of the training regimen was 10 weeks. Liver GLY content (mmoles/g) for the exercise trained groups was significantly higher (p < 0.01) than CON. There were no significant differences between RUN and SWIM animals in the GLY levels of the hindlimb muscles. The GLY levels of the forelimb muscles were significantly greater (p0.01) in the SWIM animals compared to the RIJN animals, apart from the pectoralis (EEC). The CS activity in the soleus (SOL) and red -vastus (RV) of the RUN animals was significantly larger (p <; 0.01) than SWIM. The plantaris (PLANT) of the SWIM animals had significantly greater CS activity than the RUN animals. In the forelimb muscles, only -the deltoid (DEL) of the SWIM group was higher in CS activity than the RUN groups. The results of this study indicate that the mechanisms responsible for increased GLY storage in skeletal muscle are under independent control to those factors governing the changes in the oxidative enzyme CS. Differences in muscle GLY levels and CS activity between RUN and SWIM rats can be explained by contrasting mechanics in these two (nodes of exercise and the resulting fiber recruitment patterns.

The effects of short term exposure (5 minutes) to EEFs at relatively high dosages (10, 25, 39, kV/m) on the electrical activity in rat pineal glands was studied. Daytime and nighttime recordings were taken from an implanted microelectrode in the gland. The data show that (1) both the activity and frequency were enhanced when the animals were exposed to EEFs at 39 kV/m continuously and discontinuously; (2) the later condition yielded a sustained increase (36%) whereas the former a brief (10 sec) increase. This enhancement was statistically significant under both conditions (day and night). The effects observed were thought to be due to membrane alterations either in the pineal gland itself or in the neural inputs to the gland.

by Chang Chuen Chung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 125-140). / Acknowledgement --- p.4 / List of Abbreviations --- p.5 / Abstract --- p.7 / Chapter CHAPTER I --- INTRODUCTION --- p.10 / Chapter 1.1 --- Astrocytes in the Central Nervous System --- p.10 / Chapter 1.1.1 --- Characteristics of astrocytes --- p.10 / Chapter 1.1.2 --- Functional roles of astrocytes --- p.11 / Chapter 1.1.2.1 --- General functions of astrocytes --- p.11 / Chapter 1.1.2.2 --- Volume regulation of astrocytes in CNS injuries --- p.12 / Chapter 1.1.2.3 --- Immunological functions of astrocytes --- p.13 / Chapter 1.2 --- Taurine in the CNS --- p.15 / Chapter 1.2.1 --- The biochemistry and distribution of taurine --- p.15 / Chapter 1.2.2 --- Physiological functions of taurine in the CNS --- p.19 / Chapter 1.2.3 --- Uptake and release of taurine by cultured astrocytes --- p.20 / Chapter 1.2.3.1 --- Taurine uptake in astrocytes --- p.21 / Chapter 1.2.3.2 --- Taurine release in astrocytes --- p.22 / Chapter 1.3 --- Tumor necrosis factor in the CNS --- p.23 / Chapter 1.3.1 --- Characteristics of tumor necrosis factor --- p.23 / Chapter 1.3.2 --- Sources of TNF in the CNS --- p.25 / Chapter 1.3.3 --- Functions of TNF in the CNS --- p.26 / Chapter 1.3.4 --- TNF and signal transduction --- p.27 / Chapter 1.4 --- cGMP second messenger system in astrocyte --- p.29 / Chapter 1.4.1 --- cGMP as second messenger in astrocytes --- p.29 / Chapter 1.4.2 --- Post cGMP cascade effects --- p.30 / Chapter 1.5 --- The aims of this project --- p.30 / Chapter CHAPTER II --- METHODS --- p.34 / Chapter 2.1 --- Primary astrocytes culture --- p.34 / Chapter 2.1.1 --- Primary rat astrocytes culture --- p.34 / Chapter 2.1.2 --- Primary mouse astrocytes culture --- p.36 / Chapter 2.1.3 --- Culture of rat C6 glioma cell line --- p.36 / Chapter 2.1.4 --- Subculture of astrocytes in different media --- p.37 / Chapter 2.2 --- Taurine uptake and release assay --- p.39 / Chapter 2.2.1 --- Taurine uptake assay --- p.39 / Chapter 2.2.2 --- Taurine release assay --- p.41 / Chapter 2.3 --- The effects of TNF on taurine transport --- p.42 / Chapter 2.4 --- The effects of TNF on cell volume in astrocytes --- p.43 / Chapter 2.5 --- "The effects of TNF on amino acids, glucose and neurotransmitters uptake" --- p.43 / Chapter 2.5.1 --- The effects of TNF on amino acids uptake --- p.43 / Chapter 2.5.2 --- The effects of TNF on glucose uptake --- p.44 / Chapter 2.5.3 --- The effects of TNF on neurotransmitters uptake --- p.45 / Chapter 2.6 --- The effects of LPS on taurine uptake in astrocytes --- p.46 / Chapter 2.7 --- The effects of IFN-¡’ on taurine uptake in astrocytes --- p.46 / Chapter 2.8 --- The effects of PMA on taurine uptake in astrocytes --- p.47 / Chapter 2.9 --- "The effects of TNF on thymidine, uridine and leucine incorporation in astrocytes" --- p.47 / Chapter 2.10 --- The effects of TNF on basal level of cGMP in astrocytes --- p.48 / Chapter 2.11 --- The effects of TNF on protein phosphorylation in astrocytes --- p.49 / Chapter 2.12 --- The effects of TNF on calcium uptake in astrocytes --- p.50 / Chapter CHAPTER III --- RESULTS --- p.51 / Chapter 3.1 --- The effects of TNF on taurine transport in cultured rat astrocytes --- p.51 / Chapter 3.1.1 --- The effects of TNF on [3H]-taurine uptake -time course study --- p.52 / Chapter 3.1.2 --- The effects of TNF on the kinetic parameters of the taurine uptake system --- p.54 / Chapter 3.1.3 --- The effects of TNF concentration on taurine uptake --- p.63 / Chapter 3.1.4 --- The effects of TNF exposure time on taurine uptake --- p.65 / Chapter 3.1.5 --- The effects of TNF on cell volume change in astrocytes --- p.67 / Chapter 3.1.6 --- "Comparison of the effects of TNF on taurine uptake amongst cultured primary rat astrocytes, primary mouse astrocytes and C6 glioma cell line" --- p.69 / Chapter 3.1.7 --- The effects of TNF on taurine release --- p.71 / Chapter 3.1.8 --- The specificity of the effects of TNF on taurine uptake --- p.74 / Chapter 3.1.8.1 --- The effects of TNF on the uptake of amino acids and glucose in primary rat astrocytes --- p.79 / Chapter 3.1.8.2 --- The effects of TNF on neurotransmitters uptake --- p.87 / Chapter 3.1.9 --- The effects of LPS on taurine uptake in astrocytes --- p.92 / Chapter 3.1.10 --- The effects of IFN-¡’ on taurine uptake in astrocytes --- p.97 / Chapter 3.1.11 --- The effects of PMA on taurine uptake --- p.99 / Chapter 3.2 --- The effects of TNF on cell metabolism in rat astrocytes --- p.102 / Chapter 3.2.1 --- The effects of TNF on astrocyte proliferation --- p.102 / Chapter 3.2.2 --- The effects of TNF on RNA synthesis --- p.103 / Chapter 3.2.3 --- The effects of TNF on protein synthesis --- p.106 / Chapter 3.2.4 --- The effects of TNF on basal level of cGMP --- p.108 / Chapter 3.2.5 --- The effects of TNF on protein phosphorylation --- p.111 / Chapter 3.2.6 --- The effects of TNF on calcium uptake --- p.113 / Chapter Chapter IV --- DISCUSSION AND CONCLUSION --- p.116 / References --- p.125

Abstract not available