Biliary excretion of 7Be and its distribution after intravenous administration of 7BeCl2 in rats

Wistar female rats were given two i.v. doses of 7BeCl2 (dose A = 0.025 mg Be2+/kg b.w.; dose B = 0.25 mg Be2+/kg b.w.). The rats were decapitated at 5, 24, and 48 hrs after administration. The kinetics of 7Be bile excretion during the 5 hrs after administration, as well as 7Be retention in selected organs and the urine and stool excretion of beryllium were investigated. Significant differences between the effect of both doses were found particularly in the shape of biliary excretion curves of 7Be. Unproportionally higher 7Be blood levels after a higher dose persisted for a longer period of time. The decrease of 7Be in blood after a higher dose between the 5th and 24th hr after the administration was accompanied by an increased content of 7Be in the liver and spleen as well as by an increased urine excretion. The results obtained tend to prove that the reticuloendothelial system mainly participated in beryllium retention. Urine represents the main excretion route of beryllium after a parenteral administration.