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dc.contributor.authorMcAllister-Irwin, Nancy Lynn.en_US
dc.date.accessioned2014-10-21T12:37:03Z
dc.date.available2014-10-21T12:37:03Z
dc.date.issued1995en_US
dc.identifier.otherAAINN05285en_US
dc.identifier.urihttp://hdl.handle.net/10222/55067
dc.descriptionA consequence of variable oxygen partial pressures in aquatic environments, is that all fish share some degree of hypoxia tolerance. The hierarchical recruitment of physiological and biochemical defence mechanisms and the degree of their success in protecting the animal against losses of oxygen to vital tissues, appears to be species dependent. Animals, like the goldfish (Carassius auratus) that thrive in low oxygen environments, employ a whole host or mechanisms to ensure continued viability. The two major strategies are (1) metabolic depression and (2) maintenance or intracellular ion homeostasis via channel regulation.en_US
dc.descriptionGoldfish and trout red blood cells display similar metabolic and ionic responses to an acute hypoxic exposure. However, goldfish RBC's incubated in nitrogen for 60 minutes prior to sampling do not display changes of energy concentrations (ATP) or intracellular sodium and potassium ions typical of the less hypoxia-tolerant trout. Even when adrenergically challenged, these red cells maintained their metabolic-membrane coupling. This suggests a reduced metabolism as energy consumption and energy production are matched. The absence of an adrenergic response is also typical of animals that are 'good animal anaerobes'.en_US
dc.descriptionRed cells incubated with ouabain (a sodium-potassium ATPase blocker) do not show the changes in intracellular ion concentrations seen in the rainbow trout. This supports the notion that channel arrest is integral to survival in low ambient oxygen concentration for the goldfish.en_US
dc.descriptionAnother evolutionary adaptation for a lifestyle which requires an ability to survive extended hypoxia is an organism's ability to deal with acid-base imbalances. This is reflected in their buffering capacity and Haldane effect.en_US
dc.descriptionThesis (Ph.D.)--Dalhousie University (Canada), 1995.en_US
dc.languageengen_US
dc.publisherDalhousie Universityen_US
dc.publisheren_US
dc.subjectBiology, Animal Physiology.en_US
dc.subjectAgriculture, Fisheries and Aquaculture.en_US
dc.titleMetabolism and ion exchange in nucleated erythrocytes of the hypoxia-tolerant goldfish, Carassius auratus, and hypoxia-sensitive rainbow trout, Oncorhynchus mykiss.en_US
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dc.contributor.degreePh.D.en_US
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