Free 67Ga enters into the hepatocytes of carbon tetrachloride-treated rats

Gallium-67 (67Ga) has been used as tumor or inflammation-imaging agent in nuclear medicine for decades. Although many hypotheses concerning the mechanism of uptake of 67Ga into tumors and inflammation have been proposed, consensus has not been reached. If the mechanism of 67Ga uptake is clarified, we can improve the sensitivity of diagnostic imaging with 67Ga. We attempted to clarify the mechanism of 67Ga uptake by the liver of carbon tetrachloride (CCl(4))-treated rats. First, we investigated whether or not transferrin (Tf) is involved in 67Ga uptake by the liver tissue of CCl(4)-treated rats. It is well known that Fe(3+) can inhibit the binding of 67Ga to Tf. The administration of FeCl(3) 5 min before the injection of 67Ga slightly enhanced the uptake of 67Ga by the liver tissue of CCl(4)-treated rats. The entering of 67Ga into hepatocytes of CCl(4)-treated rats was similar to the uptake by the liver tissue. In addition, the administration of FeCl(3) slightly increased the entering of 67Ga to hepatocytes. These results suggest that free 67Ga enters into hepatocytes from the liver of CCl(4)-treated rats.