The choroid plexus and cerebral vasculature as target sites for cadmium following acute exposure in neonatal and adult mice: an autoradiographic and gamma counting study

Abstract

The relationship between postnatal age at time of cadmium (Cd) exposure, and the retention and distribution of Cd in the central nervous system (CNS) was studied using gamma counting and autoradiography. A single intraperitoneal dose of Cd2+ (84 micrograms/kg or 750 micrograms/kg) containing radioactive 109Cd, was administered on postnatal day 0, 7, 14, or 42. Animals were then killed at various times post exposure (1-115 days) and retention and distribution determined. Maximum retention of Cd in the brain (calculated as a percentage of administered dose) occurred 1-24 days after exposure. Following exposure on day 0, 7, 14, or 42, maximum retention was 1.2%, 1.6%, 0.4%, or 0.09%, respectively. Cd retention after 114 days was 0.3%, 1.0%, 0.1%, or 0.04% for the respective days of exposure. For the carrier-added group maximum retention was higher with corresponding figures of 2.3%, 1.6%, 1.4%, or 0.07% and retention after 114 days was also elevated 0.6%, 1.1%, 0.4%, or 0.04%. The autoradiographic studies indicated that the choroid plexus was the prime target for Cd uptake in the CNS for all age groups, with the blood vessels a target in the early postnatal period.