Uptake of radioactive elements in rat brain tumor

Based on our previous finding that Zn is preferentially taken up in rat brain tumors, we examined the uptake of various radioactive elements in a rat brain tumor by using the multitracer technique. The multitracer solution was intravenously injected into rats 14 days after intrahippocampal injection of C6 glioma. Brain distribution and blood level of radioactive elements were determined 1 h after injection of the multitracer solution. Fifteen radioactive elements were detected in the brain and/or blood. Zn, Rb, and Mn were preferentially taken up in the tumor, compared to other radioactive elements. The uptake rates of Zn, Rb, and Mn in the tumor were significantly higher than in the cerebral cortex, cerebellum, the rest of the brain and in the blood. These results suggest the potentiality of radioactive rubidium and manganese, in addition to radioactive zinc, for brain tumor imaging.