Biology ETDs

Publication Date



The excretion rates and distribution of cesium-137 and sodium-22 were studied in white rats exposed to cold or over-hydration, or both.

A single intraperitoneal injection of cesium-137 or sodium-22 was administered to rats housed in metabolic cages. Rate of isotope excretion was determined by daily measurements of urine, feces, and the whole animal with a gamma scintillation spectrometer.

In one study rats were injected intraperitoneally with saline solution equivalent to 10% of the body weight one hour after having been injected with cesium-137. After 23 hours the rats were sacrificed and individual tissue counts were taken to be compared with the final whole-body count in order to determine Tissue Retention Indices, which are an expression of tissue distribution of isotope. Injection of saline one hour after administration of cesium-137 caused no increase in excretion rate nor change in tissue distribution of cesium-137.

In additional studies rats were treated with hypothermia or saline loading, or both, at the first biological half-time and sacrificed at the second biological half-time. The first biological half-time varied from 7.0 to 15.3 days for cesium-137 and 6.9 to 8.2 days for sodium-22 or cesium-137 excretion. Saline overload caused a temporary increase in excretion rate of sodium-22 but did not affect excretion of cesium-137.

Project Sponsors

Atomic Energy Comission Research Contract AT(29-2)-1629



Document Type


Degree Name


Level of Degree


Department Name

UNM Biology Department

First Committee Member (Chair)

Marvin LeRoy Riedesel

Second Committee Member

Raymond N. Castle

Third Committee Member

William Jacob Koster

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Biology Commons