1. Two aspects of long-term salt and water excretion were measured in Glaucous-winged Gulls, Larus glaucescens. Total body water volume and turnover rate were measured in birds drinking fresh water and drinking sea water by THO disappearance rate. Na+, K+, and CI- excretions over 24 hours were measured by continuous collection of cloacal and salt gland excretions from birds fed fish, fish plus a salt load, or a salt load only. 2. Total body water volume was found to be 79% of body weight on both fresh water and sea water drinking regimes. TBW volume is large compared to other birds. 3. Mean total body water turnover rate was the same for both drinking regimes (0.064 ml/g-day); this value is the same as the predicted rate based on data from other birds. 4. There were no significant differences between the fish and fish salt fed birds in the pattern or amounts of ion excretion. 5. Sodium and chloride were excreted in approximately equal amounts from the salt gland and cloaca. Most potassium was excreted via the cloaca. Thirty-eight percent of the total sodium, 6% of the total potassium and 58% of the total chloride excreted were contained in the salt gland secretion of both the fish and fish + salt groups of gulls. 6. The fluid and solid portions of the cloacal excretion were analyzed for ions. Cations were divided between the two portions. In the fish and fish + salt fed birds, 51.8 + 7.8% of the cloacal Na+ and 61.8 + 4.5% of the cloacal K+ was found in the solid portion of the cloacal excreta. Chloride was detected in the fluid portion only. 7. The two birds given only a salt load had lower rates of evaporative water loss and smaller amounts of cloacal solids compared to the fed birds. 8. The large TBW volume may be advantageous to marine birds as a buffer against excess salt ingestion. The constancy of TBW turnover rate suggests that the gulls are specifically adapted to their environment where salt, but not water, is a stress. 9. The results suggest that the salt gland, cloacal fluids and especially the cloacal solids are important routes for ion excretion for fed birds and that osmoregulatory processes for fed and unfed birds may be different. 10. These data imply that although the salt gland is the primary adaptation of marine birds to salt stress, the entire process of salt and water metabolism also involves other more subtle mechanisms. / Science, Faculty of / Zoology, Department of / Graduate

No description available.

published_or_final_version / Physiology / Master / Master of Philosophy

Thesis (M.S.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2031-01-01

by Wong Chi Shing Micky. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 140-149). / Chapter Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- The Uterine Cervix --- p.1 / Chapter 1.2 --- Cervical Secretion and its Function --- p.3 / Chapter 1.3 --- Ion Transport System in Cell Volume Regulation --- p.6 / Chapter 1.3.1 --- "Regulatory Volume Decrease, RVD" --- p.8 / Chapter 1.3.2 --- "Regulatory Volume Increase, RVI" --- p.8 / Chapter 1.4 --- Signaling Pathways underlying RVD and RVI - The Role of Intracellular Free Calcium --- p.11 / Chapter 1.5 --- Swelling-induced Cl- Current --- p.12 / Chapter 1.6 --- Ca2+ activated K+ Channel --- p.14 / Chapter 1.7 --- Objectives of the Study --- p.15 / Chapter Chapter 2. --- Materials and Methods --- p.17 / Chapter 2.1 --- Materials --- p.17 / Chapter 2.1.1 --- Culture Media --- p.17 / Chapter 2.1.2 --- Chemicals --- p.17 / Chapter 2.2 --- Preparation of Solutions --- p.18 / Chapter 2.3 --- Cell Culture --- p.21 / Chapter 2.4 --- Patch-clamp Technique --- p.22 / Chapter 2.4.1 --- Preparation of Electrode --- p.27 / Chapter 2.4.1.1 --- Pulling and Polishing of Electrode --- p.27 / Chapter 2.4.1.2 --- Filling of the Electrode --- p.27 / Chapter 2.4.1.3 --- Coating of Electrode --- p.28 / Chapter 2.4.2 --- Patch-clamp Study --- p.29 / Chapter 2.4.2.1 --- Formation of Whole-cell Configuration --- p.29 / Chapter 2.4.2.2 --- Data Acquisition and Analysis --- p.31 / Chapter 2.5 --- Study of Cellular Volume Regulation by Confocal Laser Scanning Microscopy (CLSM) --- p.35 / Chapter 2.6 --- Determination of Intracellular Ca2+ by Confocal Laser Scanning Microscopy (CLSM) --- p.38 / Chapter Chapter 3. --- Results --- p.39 / Chapter 3.1 --- "Regulatory Volume Decrease, RVD" --- p.39 / Chapter 3.2 --- Responses of [Ca2+］i to swelling --- p.47 / Chapter 3.3 --- KC1 Efflux in RVD in HeLa Cells --- p.57 / Chapter 3.4 --- Swelling-induced Cl- Current --- p.67 / Chapter 3.4.1 --- Swelling-induced Anion and Cation Current --- p.67 / Chapter 3.4.2 --- Ca2+-independence of Swelling-induced Cl- Current --- p.71 / Chapter 3.4.3 --- Effect of Cl- Channel Blockers on Swelling-induced Cl- Current --- p.75 / Chapter 3.4.4 --- Anion Selectivity of Swelling-induced Cl- Current --- p.85 / Chapter 3.4.5 --- Cl- Dependence of Swelling-induced Cation Conductance --- p.85 / Chapter 3.4.6 --- K+ Independence of Swelling-induced Anion Conductance --- p.95 / Chapter 3.5 --- Ca2+ Activated K+ Current --- p.101 / Chapter 3.5.1 --- Ionomycin Induced Cell Shrinkage under Isotonic Condition --- p.101 / Chapter 3.5.2 --- Ionomycin Stimulated a Whole-cell K+ Conductance --- p.101 / Chapter 3.5.3 --- The Effect of Ionomycin on Intracellular Ca2+ Level --- p.111 / Chapter 3.5.4 --- Ca2+ Dependence of Ionomycin Stimulated K+ Current --- p.111 / Chapter Chapter 4. --- Discussion --- p.124 / Regulatory Volume Decrease in HeLa Cells --- p.124 / Role of Calcium in Regulatory Volume Decrease (RVD) --- p.126 / Swelling-induced Cation and Anion Conductance --- p.128 / Ca2+ Activated K+ Current in HeLa Cells --- p.134 / Chapter Chapter 5. --- Reference --- p.140

Thesis--M. Phil., University of Hong Kong, 1980.

Bibliography: leaves 219-229. / Microfiche. / xiv, 229 leaves, bound ill. 29 cm

Thesis (M. Phil.)--University of Hong Kong, 1980. / Also available in print.

Regulation of chloride, sodium, potassium, calcium, and magnesium ions was determined for hypo- and hypersaline conditions in the crab, Cancer magister, from an estuarine environment. Animals from both summer and winter were examined. Chloride regulation in the blood was hypertonic in dilute salinities and hypotonic in concentrated salinities, with summer animals maintaining a greater gradient in the former and winter animals a greater gradient in the latter. Sodium in the blood is regulated hypertonically in all experimental salinities, with summer animals maintaining a greater gradient. Blood potassium is regulated hypertonically in dilute salinities, approaching isotonicity in hypersaline media. Summer animals maintain a greater gradient of potassium concentration. Blood calcium is regulated hypertonically in all experimental salinities, with summer animals maintaining a greater gradient in dilute salinities and winter animals a greater gradient in concentrated salinities. Magnesium is regulated at a pronounced hypotonic level in the blood over the entire experimental salinity range, with winter animals maintaining the greater gradient. Major changes in the adaptation of blood ionic concentrations occur within a few hours of exposure to the experimental salinities, with half of the final equilibrated concentration values attained by twelve hours. Animal weight was found to bear no significant relationship to the ionic regulatory activity observed. Renal involvement in regulation has been shown for all the ions, with the production of a urine hypertonic to the blood for chloride and magnesium, and a urine hypotonic to the blood for sodium, potassium, and calcium. Renal regulation was greater in winter animals for chloride, and greater in summer animals for sodium and potassium. Ionic regulation by the gills of summer and winter animals was investigated by potential difference measurements, and was suggested to occur for all ions. Chloride may have been regulated by the absorption from dilute media and excretion into concentrated media. Sodium may have been regulated by secretion into dilute media. The involvement of the gill in potassium, calcium, and magnesium regulation was implicated. / Science, Faculty of / Zoology, Department of / Graduate

A Research Report submitted to the Faculty of Medicine, University of the Witwatersrand, Johannesburg in partial fulfilment for the degree of M.Sc.(Med) / During a typical swimming training session, the volume of fluid lost via sweat is not evident which may contribute to a swimmer not replacing fluid loss effectively. This study investigates fluid balance during a typical swim training session. The physiological responses measured included fluid loss, fluid gain and plasma lactate concentrations / IT2018