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The Significance Of Hypovolemia In Dehydrational Death In Anurans, Peter Blair Kimmel
The Significance Of Hypovolemia In Dehydrational Death In Anurans, Peter Blair Kimmel
Dissertations and Theses
The importance of hypovolemia in dehydrational death was assessed in two anuran species. Xenopus laeyis, a species which experiences a significant reduction in circulating plasma volume with dehydration, was used to evaluate the role of sympathetic reflex compensation in hypovolemia. Adrenergic blockade with propranolol or phenoxybenzamine produced no significant reduction in dehydration tolerance in this species, although β-blockade with propranolol appeared to have a minor effect. The role of hypovolemic shock in the terminal circulatory collapse that precedes death in dehydrating anurans was investigated in the toad, Bufo marinus. The activity of lysosomal proteinases (cathepsins) was used as an indicator …
Effects Of Dehydration On Hemoglobin Oxygen Affinity And Blood Cell Volume In Two Anurans, Andrew Christopher Zygmunt
Effects Of Dehydration On Hemoglobin Oxygen Affinity And Blood Cell Volume In Two Anurans, Andrew Christopher Zygmunt
Dissertations and Theses
Two aspects of possible adaptation in cardiovascular performance caused by increased plasma electrolytes were examined. Cells in anisotonic plasma may either act as osmometers or volume regulate. Blood flow rate is dependent upon cell viscosity, which in turn is a consequence of cell volume and membrane deform-ability. Cell volume changes which increase membrane deform-ability will thus potentially extend the limits of dehydration tolerance. It was found in R. catesbeiana and B. marinus that red blood cell is maintain constant volume during dehydration. Cells in vitro initially lose water, but then sodium, potassium and water move into the cell. Cell viscosity …