Brain regional uptake of radioactive Sc, Mn, Zn, Se, Rb and Zr tracers into normal mice during aging

Radioactive multitracer technique was applied to study the brain regional uptake of trace elements by the normal mice during aging. The brain regional radioactivities of ⁴⁶Sc, ⁵⁴Mn, ⁶⁵Zn, ⁷⁵Se, ⁸³Rb and ⁸⁸Zr were measured 48 hours after intraperitoneal injection of a solution in normal mice aged 6 to 52 weeks to evaluate the brain regional (corpus striatum, cerebellum, cerebral cortex, hippocampus, and pons and medulla) uptakes. The radioactive distributions of ⁴⁶Sc, ⁵⁴Mn and ⁸⁸Zr tracers were variable and region-specific in the brain, while those of ⁶⁵Zn, ⁷⁵Se and ⁸³Rb tracers were comparable among all regions of interest. The brain regional uptakes of all tracers slightly increased with age from 10 to 28 weeks, and then remained constant during aging after 28 weeks. These uptake variations may be involved in the functional degenerative process of the blood-brain barrier during aging.