Organ uptake and plasma transportation kinetics of hemoglobin in rats

The Formation of Bilirubin From Hemoglobin in Vivo*

“…As expected (15,29), virtually all sensitized red cells were sequestered in approximately equal proportions by spleen and liver, with no significant uptake of Cr51 or Fe59 by the kidneys nor significant excretion of radioactivity in the urine. After injection of comparable quantities of hemoglobin solution, clearance from the circulation also was virtually complete, but the tissue distribution of radioactivity was different (23,30). Hepatic uptake greatly exceeded splenic uptake, which was never more than 3 per cent of the injected dose.…”

“…In the present experiments rats with a bile fistula were given an intravenous injection of one of the following heme pigment preparations: 1) suspensions of antibody-sensitized red cells which were primarily sequestered in the spleen and liver (15,29); or 2) various amounts of hemoglobin in solution, which were predominantly removed by the liver and the kidneys (23,30,31). In spite of these differences, the labeled heme pigment was cleared from the circulation and excreted as radioactive bilirubin in the bile at similar rates.…”

“…The liver, spleen, kidneys, lungs, and right femur were removed, blotted with damp gauze, weighed, and the Fe 5' activity determined on specimens not exceeding 2 g in weight (14). Total Fe" in the marrow was roughly estimated by multiplying the femur radioactivity by 14.4 (23 ). Urine and bile Fe"' or Cr5' radioactivity were determined on the total 22-hour specimens.…”

Disposal of plasma heme in normal man and patients with intravascular hemolysis

“…4). Previous studies have shown that the liver is also the site of removal of protein-bound heme in animals (21,22) and of free and haptoglobin-bound hemoglobin in animals (35,43,48) and man (15,16 Reutilization of heme-iron (Fig. 4).…”

Renal Salvage of Haemoglobin Iron

“…When haptoglobin bound 59FeFHb is injected into normal animals, 62 % of the radioactivity is located to the liver which is the major organ normally associated with Hb catabolism, and only 0.5 % are found in the kidneys (Garby & Obara 1960, Hershko et a1 1972. Renal uptake of Hb in sigmficant amounts requires prior depletion of circulating haptoglobin.…”