Summary The uptake of transferrin and iron by rat liver tissue was measured using in vivo screened radioiodinated rat albumin and transferring, 59Fe and three experimental techniques using liver slices, the isolated perfused liver or the intact animal. Uptake of labelled transferrin in excess of that of albumin relative to their concentrations in the solutions bathing the liver cells was found with all three techniques. This was considered to represent specific uptake of transferrin by liver cells. It occurred rapidly to reach an equilibrium within 30 min in the perfused liver and the intact animal but was slow with liver slices. More than half of the transferrin specifically bound by the liver in vivo was released into the perfusate during subsequent perfusion. Radioiron uptake in excess of radioiodinated transferrin uptake was also found with all three techniques and was used to measure the rate of cellular uptake of iron. This was tow with liver slices but the values for the perfused liver were comparable to the rate found in vivo. It is concluded that transferrin is reversibly taken up by rat liver cells, probably during the process of assimilation of plasma iron, and that the isolated perfused liver is superior to liver slices as a technique to study the mechanism of iron uptake by the liver.

No abstract

No abstract