BILIARY EXCRETION OF RADIOACTIVE IRON AND TOTAL IRON AS INFLUENCED BY RED CELL DESTRUCTION.

Iron is eliminated in the bile of normal dogs at a low but quite constant rate, 0.2 mg. per day. The feeding of large amounts of iron to normal dogs does not cause an increased iron excretion in the bile nor does the injection of considerable quantities of colloidal iron by vein. When red cell destruction is brought about by acetyl-phenylhydrazine the elimination of biliary iron may increase tenfold and parallels the increased output of bile pigment. When red cells containing radioactive iron are destroyed by acetyl-phenylhydrazine there is a significant increase in radioactive iron excreted in the bile which parallels the bile pigment excretion-Charts A and C. The excretion of iron and bile pigment is independent of the volume of bile. When hemoglobin is destroyed the pigment radicle is totally excreted as bile pigment but only 3 per cent of the released iron is eliminated in the bile with conservation of the remainder. The importance of the liver and spleen as storehouses of iron is again confirmed. The body conserves iron even when it is present in marked excess.