Tag Archives: cadmium

Biochemical mechanisms of free-radical damage to the nuclear genome by cadmium

I. M. Trakhtenberg1, Y. I. Gubsky2, E. L. Levitsky3, I. F. Belenichev4

1Institute of Occupational Medicine, National Academy of Medical Sciences of Ukraine, Kyiv;
2Insitute of Pharmacology and Toxicology, National Academy of Medical Sciences of Ukraine, Kyiv;
3Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: levitsky@biochem.kiev.ua;
4Zaporozhye State Medical University of the Ministry of Health of Ukraine

Cadmium, has been used for many years in industry and agriculture. Its active use is associated with a danger to human health due to a significant toxic effect on the body. The purpose of the review was to analyze the literature data and the results of our own experimental research on the biochemical mechanisms of the toxic effect of cadmium on the nuclear chromatin of cells, primarily the liver. Based on this analysis, the concept that the toxicity of cadmium is associated with damage caused by cadmium-induced free radicals was confirmed. The reactive oxygen species formed in this way are active damaging agents that cause toxic effects, including mutagenic, which ultimately leads to apoptosis and cell death.

Glutathione level of Desulfovibrio desulfuricans ІМV K-6 under the influence of heavy metal salts

I. V. Kushkevych, S. O. Hnatush, H. V. Mutenko

Ivan Franko Lviv National University, Ukraine;
e-mail: Ivan_Kushkevych@ukr.net

Glutathione is the metal stress protector and changes of its level in the sulfate-reducing bacteria cells under the influence of heavy metal salts have not been studied yet. CdCl2, Pb(NO3)2, CuCl2, and ZnCl2 influence on the total glutathione level in cell-free extracts of sulfate-reducing bacteria Desulfovibrio desulfuricans ІМV K-6 was studied. The research has been carried out using Ellman, Lowry methods, statistical processing of the results. It was shown that the glutathione level depends on the heavy metal salts concentration in the medium. The total glutathione level was the highest under the influence of Pb(NO3)2. Other salts were also toxic to bacteria because glutathione level increased in bacterial cells after addition of these salts to the medium. On the basis of the results of our work the range of heavy metal salts influence on D. desulfuricans ІМV K-6 cells glutathione level has been formed for the first time: Pb(NO3)2 > CuCl2 > CdCl2 > ZnCl2.

Metal-binding capacity of metallothioneins of the liver of rats poisoned with heavy metals

B. O. Tsudzevich, I. V. Kalinin

Taras Shevchenko Kyiv National University, Ukraine;
е-mail: ikalin@rambler.ru

The functioning of metallothioneins in the liver of rats, poisoned with copper sulfate and cadmium sulfate has been investigated. By sequential chromatography on sephadex G-50 and DEAE-cellulose the authors obtained metallothioneins (MT-1, MT-1A, MT-2, MT-2a), which differ in molecular weight and composition of associated metals. Heavy metal poisoning leads to activation of synthesis and metal-binding function of metallothioneins, as well as to changes in the composition of their isoforms.

Distribution of glial fibrillary acidic protein in different parts of the rat brain under cadmium exposure

Yu. P. Kovalchuk1, I. V. Prischepa1, U. Si2, V. S. Nedzvetsky1,
Y. G. Kot2, E. E. Persky2, G. A. Ushakova1

1Oles’ Honchar Dnepropetrovsk National University, Ukraine;
2V. N. Karazin  Kharkiv National University, Ukraine;
e-mail:  yulka.kovalchuk.5868152@mail.ru

The chronic effects of low doses of cadmium on the distribution of soluble and filament forms of glial fibrillary acidic protein (GFAP) and their polypeptide fragments in different parts of the rat brain were investigated. Obtained results showed dose-dependent effect of cadmium on the soluble form of GFAP and more pronounced effect on the filament form and composition of the polypeptide fragments of the protein in the rat brain. Prolonged intoxication by cadmium ions in a dose of 1.0 µg/kg of body weight induced a significant decrease in soluble GFAP and an increase in the filament form in the rat brain, pointing to the development of reactive astrogliosis and the risk of neurodegeneration.

Transcriptional regulation of the Hansenula polymorpha GSH2 gene in the response to cadmium ion treatment

O. V. Blazhenko, А. B. Kotlyarchuk, V. M. Ubiyvovk

Institute of Cell Biology, National Academy of Science of Ukraine, Lviv;
e-mail: Oleksandra.Blazhenko@googlemail.com

In a previous study we cloned GSH2 gene, encoding γ-glutamylcysteine synthetase (γGCS) in the yeast Hansenula рolymorpha. In this study an analysis of molecular organisation of the H. рolymorpha GSH2 gene promoter was conducted and the potential binding sites of Yap1, Skn7, Creb/Atf1, and Cbf1 transcription factors were detected. It was established that full regulation of GSH2 gene expression in the response to cadmium and oxidative stress requires the length of GSH2 promoter to be longer than 450 bp from the start of translation initiation. To study the transcriptional regulation of H. polymorpha GSH2 gene recombinant strain, harbouring­ a reporter system, in which 1.832 kb regulatory region of GSH2 gene was fused to structural and terminatory regions of alcohol oxidase gene, was constructed. It was shown that maximum increase in H. polymorpha GSH2 gene transcription by 33% occurs in the rich medium under four-hour incubation with 1 μM concentration of cadmium ions. In the minimal medium the GSH2 gene expression does not correlate with the increased total cellular glutathione levels under cadmium ion treatment. We assume that the increased content of total cellular glutathione under cadmium stress in the yeast H. polymorpha probably is not controlled on the level of GSH2 gene transcription.