Studies on Renal Excretion of Beryllium. ∗

Abstract

Summary

Carrier-free Be⁷ injected in an insoluble form has a very low clearance as compared with the simultaneous inulin clearance. When citrate, a potent complexer of beryllium, is added to insure that the injected beryllium is in an insoluble form, the clearance is much greater, despite the fact that ultrafiltration studies indicate the soluble beryllium to assume a non-diffusible form after mixing with the blood. The addition of carrier does not markedly alter the beryllium clearance. The clearance ratio, i.e., C_Be/C_inulin, varies widely enough to suggest that the two substances are not excreted by the same mechanism, and the possibility of tubular activity in beryllium excretion comes to mind. This idea is supported by ultrafiltration studies which show that beryllium exists in the plasma in a non-diffusible form. Complete clarification of the problem must await further work on the state of beryllium in the blood.