Mercury distribution in the rat brain after mercury vapor exposure

Brown Norwegian rats were exposed to mercury vapor at a concentration of approximately 1 mg/m3 for 5 weeks 24 hr/day 7 days a week and 6 hr/day 3 days a week, respectively. The total mercury absorption was calculated to 264 and 35 micrograms per week and 100 g body weight. The mean blood mercury concentration was 0.25 +/- 0.03 and 0.09 +/- 0.01 microgram/g, and the total concentration in the brain was 5.03 +/- 0.73 and 0.71 +/- 0.10 microgram/g tissue, respectively. The mercury distribution in the brains was examined using a method based on chemographic principles. Mercury was found primarily in the neocortex, in the basal nuclei, and in the cerebellar Purkinje cells. This distribution pattern corresponded to the pattern of inorganic mercury described after exposure to methyl mercury. Distribution of mercury after administration of different mercury compounds is discussed.