The distribution of tracer doses of cadmium in the normal rat.

The distribution and excretion of a single tracer dose of cadmium-109 given intravenously to rats were studied in a 60-day time course experiment. The organs that accumulated the most cadmium were the liver, kidneys, and pancreas. Initial high plasma levels decreased rapidly, and most of the cadmium that remained in the blood after 24 hr was found in the red cells. In most organs and tissues a level was reached within 24 hr at which the cadmium concentration remained relatively stable. Kidney was a marked exception because the amount of cadmium found in that organ increased progressively. Excretion of cadmium was found to be predominantly via the feces. Twenty-five to 28% of the dose was excreted by that route in 60 days, the most rapid phase occurring during the first three days. Less than 0.15% of the dose was excreted via the urine.