Autoradiographic localization of cadmium in the rat brain.

Adult rats were injected intravenously with 109CdCl2 and the distribution of the isotope within the brain and neighboring nervous structures was subsequently studied by autoradiography. Cadmium accumulated in regions outside the blood-brain barrier such as the choroid plexus, pineal gland and area postrema, but did not appear in the brain parenchyma. Uptake of cadmium was observed in the trigeminal ganglia close to the nerve cells and in the olfactory bulbs. In addition, cadmium accumulated in the iris, ciliary body and choroid of the eye, but not in the optic nerves. The deposition of cadmium in the olfactory bulbs may be related to the anosmia reported in workers exposed to this metal. The possible harmful effects of accumulation of cadmium in restricted regions of the brain and adjacent nervous structures are discussed.