Distribution in the rat of physiological amounts of injected Cr51(III) with time

Abstract

Cr51 trichloride was injected intravenously into rats at the levels of 0.01 and 0.1 µg Cr/100 g body wt and its distribution was studied at timed intervals from 1/4 hr to 4 days. There was little difference in blood clearance, tissue distribution, or excretion due to either dose level, previous diet, or sex. After 4 days, the heart, pancreas, lung, and brain retained only 10–31% of their initial radioactivity while the spleen, kidney, testis, and epididymis retained from 104 to 200%. The other tissue values were intermediate. The spleen and kidney continued to concentrate Cr51 over the 4-day period while the peak retention in the testis and epididymis was at 4 and 8 hr, respectively. Young growing rats retained greater amounts of Cr51 in the bones whereas mature animals showed higher retention in the spleen, kidney, testis, and epididymis. Chromium was excreted mainly in the urine although minor amounts were found in the feces.