title: Implication of the differential roles of metallothionein 1 and 2 isoforms in the liver of rats as determined by polyacrylamide-coated capillary zone electrophoresis.
abstract: Metallothioneins (MTs), determined by polyacrylamide-coated capillary zone electrophoresis (CZE), coincided well with those described by enzyme-linked immunosorbent assay. By using CZE, MT isoforms 1 (MT-1) and 2 (MT-2) were well separated and determined in the liver cytosol of LEC rats and Wistar rats administered CdCl(2). The total concentrations of MTs in the liver cytosol of LEC rats increased age-dependently as 1.0, 2.1, and 7.2mg/g wet weight of the liver at the age of 5, 10, and 15 weeks, respectively, and those of Wistar rats that had received daily CdCl(2) also increased with time of CdCl(2) as 0.5 and 1.2mg/g wet weight of the liver for 3 and 6 consecutive administration days, respectively. The MT-1/MT-2 ratio in the liver cytosol of LEC rats decreased age-dependently as 1.75, 1.49, and 0.76 at the age of 5, 10, and 15 weeks, respectively. In contrast, that of Wistar rats increased with time of exposure to the metal ion CdCl(2) as 1.1 and 1.6 for 3 and 6 administration days, respectively. Copper accumulation in the liver of LEC rats has already been reported. The present results indicated that the mechanism of the induction of MT synthesis differs between LEC rats, who lack ATP7B, and Wistar rats, who were given a toxic metal ion. On the basis of these results, we propose that MT-1 is related to the metabolism or detoxification of toxic metals such as Cd, and in contrast, MT-2 is responsible for the homeostasis of essential metals such as Cu.
authors.affiliation: Department of Analytical and Bioinorganic Chemistry, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Nakamura
authors.forename: Takumi
authors.initials: T
authors.lastname: Kawata
authors.forename: Akihiro
authors.initials: A
authors.lastname: Nakayama
authors.forename: Kanenobu
authors.initials: K
authors.lastname: Kubo
authors.forename: Takeshi
authors.initials: T
authors.lastname: Minami
authors.forename: Hiromu
authors.initials: H
authors.lastname: Sakurai
mesh_terms: D000180:Acrylic Resins; D000818:Animals; D019075:Electrophoresis, Capillary / Q000379:methods*; D008099:Liver / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D008668:Metallothionein / Q000737:chemistry / Q000145:classification / Q000378:metabolism*; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism; D011817:Rabbits; D051381:Rats; D020318:Rats, Long-Evans; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013045:Species Specificity; D013329:Structure-Activity Relationship; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D008668:Metallothionein; D020033:Protein Isoforms; D000099166:Polyacrylamides