Retention organ distribution, and excretory pattern of cadmium orally administered in a single dose to two monkeys.

Retention, excretion, and organ distribution of radioactive Cd were observed after a single oral dose of two monkeys. The retention rate of Cd 19 d after the administration of radiocadmium (109CdCl2, carrier-free) to one monkey was 5.2% of the administered dose; 73.4% of the dose was excreted in the feces and 0.7% in the urine. The largest fractions of the administered dose were found in the small intestine, liver, and kidney. The absorption rate of Cd 25 d after the administration of radiocadmium with 1.0 mg cold Cd as CdCl2 solution to the othermonkey was 6.3% of the administered dose; 75.5% of the dose was excreted in the feces and 0.9% in the urine. Setting the whole body retention equal to 100% on d 19 or 25, the largest fractions were found in the small intestines (51.5 and 36.3%), livers (21.8 and 29.6%), and kidneys (13.4 and 21.0%) of the respective monkeys). The effect of carrier Cd on absorption, excretion, and organ distribution was not pronounced. The highest concentration and greatest retention of Cd was observed in the upper small intestinal wall and the content of the small intestine, indicating the importance of enteroenteric circulation of the element; this finding was different from the results for Cd metabolism in rodents.