Abstract.
Previously we found that exposure to mercury vapor effectively induced brain metallothionein (MT) in rats. Here, using FPLC-gel chromatography, we examined time-dependent alterations in the MT isomers, MT-I/II and MT-III, following 3 weeks of exposure. Rats were exposed to mercury vapor at 8.3 mg/m3 for 15 h in total over 5 consecutive days. Total MT levels in rat cerebrum and cerebellum increased by 65% and 155%, respectively, 24 h after the final exposure. The increased levels in both tissues remained unchanged for at least 2 weeks after termination of exposure. Interestingly, most MT in control rat cerebrum and cerebellum was accounted for by MT-III, with MT-I/II being less than 10%. Through mercury vapor exposure, MT-I/II was quickly induced to a significant extent in both tissues, reaching a level comparable to that of MT-III. The induction rate of MT-I/II in the cerebellum was somewhat higher than in the cerebrum. Chromatograms showed that the MT-I/II thus induced began to decline at an early stage in both tissues. In the cerebrum, the amount of MT-I/II on day 22 was about 30% of the maximum level on day 1. On the other hand, the induction of MT-III was not that dramatic, but it did become evident, at least in the latter stage, when MT-I/II had begun to decrease. Thus, though the induction rate of MT-III was not as high as MT-I/II, it was sustained throughout the experimental period.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Electronic Publication
Rights and permissions
About this article
Cite this article
Yasutake, .A., Nagano, .M. & Hirayama, .K. Alterations of metallothionein isomers in Hg0-exposed rat brain. Arch Toxicol 77, 12–16 (2003). https://doi.org/10.1007/s00204-002-0410-2
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s00204-002-0410-2