The induction and synthesis of metallothionein was studied in the isolated perfused rat liver, using Cd(I1) as the inducing metal. Perfusing the liver with 25 to 100 pg of Cd(I1) for 180 min revealed that the amount of Cd(I1) in metallothionein increased with the dosage of Cd(II), saturation being achieved at 75 pg. Zn(I1) in metallothionein decreased to about 60% of the level found in control ...

Attention has focused on the cytokine interleukin 6 (IL-6) as a major mediator of acute-phase protein synthesis in hepatocytes in response to infection and tissue injury. We have evaluated the effects of IL-6 and IL-1 alpha as well as extracellular zinc and glucocorticoid hormone on metallothionein gene expression and cellular zinc accumulation in rat hepatocyte monolayer cultures. Further, we ...

Metallothionein has been implicated in resistance to anticancer drugs. We examined whether transient induction of metallothionein by dexamethasone causes resistance to cis-diamminedichloroplatinum(II) (cis-DDP) in malignant and nonmalignant cells. Normal rat kidney cells (6m2) were infected with a modified v-mos oncogene construct in which expression of v-mos and consequently transformation was...

Metallothionein has been implicated in resistance to anticancer drugs. We examined whether transient induction of metallothionein by dexamethasone causes resistance to m-diamininedichloroplatinum(II) (cisDDP) in malignant and nonmalignant cells. Normal rat kidney cells (6m2) were infected with a modified \-mos oncogene construct in which expression of \-mos and consequently transformation was t...

Metallothionein was purified under anaerobic conditions from livers of human fetuses ranging from 19 weeks gestational age to term. Homogeneous metallothionein obtained in the absence of reducing agents from the soluble fraction of the tissue which contained 24% and 85% of the total liver copper and zinc, respectively, had less than 1 g atom of copper and about 3.1 g atoms of zinc/mol. Extracti...

Metallothioneins are small, cysteine-rich proteins that avidly bind heavy metals such as zinc, copper, and cadmium to reduce their concentration to a physiological or nontoxic level. Metallothionein gene transcription is induced by several stimuli, notably heavy metal load and oxidative stress. Transcriptional induction of metallothionein genes is mediated by the metal-responsive transcription ...

OBJECTIVES to report the immunoexpression of metallothionein in oral leukoplakia and to correlate with histological grade and clinical localization. Leukoplakia is the most common potentially malignant lesion of the oral cavity. As the histological study of oral leukoplakia can not predict precisely the malignant transformation of this lesion, and metallothionein is a protein that has been asso...

Rabbit liver metallothionein depleted of Cd(II) and Zn(II) was fully reconstituted using a Cu(I)-GSH complex under strictly anaerobic conditions. Anaerobic fluorescence titration, using an emission band at 625 nm which is diagnostic of the correct insertion of Cu(I) into the thiolate clusters of metallothionein, showed that the fluorescence maximum was obtained on addition of as many Cu(I) equi...

More than 30 years have passed since the discovery of the first plant metallothionein in wheat embryos, from which the emergence of a uniquely diverse metallothionein family with a fascinating array of structural nuances and molecular properties has been witnessed. Metallothioneins are not only constitutively expressed, but the production of different types of plant metallothionein is also stim...

OBJECTIVE L-homocysteine and/or L-homocystine interact in vivo with albumin and other extracellular proteins by forming mixed-disulfide conjugates. Because of its extremely rich cysteine content, we hypothesized that metallothionein, a ubiquitous intracellular zinc-chaperone and superoxide anion radical scavenger, reacts with L-homocysteine and that homocysteinylated-metallothionein suffers los...