The effect of blood decrease on 67Ga uptake by the liver in partially hepatectomized rats

As 67Ga is injected into the blood, 67Ga is immediately bound to transferrin (Tf) and transported to various tissues and the Tf-67Ga complex binds to Tf receptor on various tissues. In partial hepatectomy (PH) a part of blood in circulation is lost together with removed liver tissues, consequently the amounts of blood cells and Tf in circulation decrease. In order to investigate the effect of those decreases on 67Ga uptake by the liver, we compared the uptake in partially hepatectomized rats with that in venesectioned rats in which only a part of blood in circulation decreased. A two-thirds PH was performed. Two milliliters of blood was venesectioned. Each treated rat was intraveneously injected with 67Ga. The changes of erythrocyte and reticulocyte contents after PH did not differ from those after venesection (VS) at all. But 67Ga uptake by reticulocytes significantly increased after VS but did not after PH. On the other hand, 67Ga uptake by the liver significantly increased after PH but did not after VS. These differences must be related to the different expression of Tf receptors on the liver after PH and VS. (author)