Tag Archives: metallothioneins

Metal-binding functions and antioxidant properties in human thyroid gland under iodine deficient nodular colloidal goiter

H. I. Falfushynska1, L. L. Gnatyshyna1, D. V. Osadchuk2, V. O. Shidlovski2, О. B. Stoliar1

1Volodymyr Hnatiuk Ternopil National Pedagogical University, Ukraine;
2Horbachevski Ternopil State Medical University, Ukraine;
e-mail: halynka.f@gmail.com

Copper and zinc levels in the tissue of thyroid gland (TG) and their metal-binding proteins metallothioneins (MT) as well as state of the antioxidant system in persons that had no thyroid disease and patients with endemic iodine deficiency nodular colloidal goiter has been investigated. In the patients with thyroid disease, oxidative damage was indicated despite elevated levels of MT-SH and glutathione, and elevated copper and decreased zinc concentration in TG tissue. MTs partly bound the excess of copper but its concentration in the unbound to MT form was two-fold compared to the control value.

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.

Functions of metallothioneins and a system of antioxidant defense under the effect of Co- and Zn-containing nanocomposites on crucian carp (Carassius auratus gibelio)

H. I. Falfushynska1,2, L. L. Gnatyshyna1, O. O. Turta1, O. B. Stoliar1,
N. E. Mitina3, O. S. Zaichenko3, R. S. Stoika4

1Volodymyr Hnatiuk Ternopil National Pedagogical University, Ukraine;
2I. Ya. Horbachevski Ternopil State Medical University, Ukraine;
e-mail: halynka.f@gmail.com;
3Lviv Polytechnic National University, Ukraine;
4Institute of Cell Biology, National Academy of Sciences of Ukraine, Lviv

The effect of metal-nanocomposites (Me-NC) of cobalt and zinc (Co- and Zn-NC, correspondingly) synthecized on the basis of vinylpyrrolidone (PS) on the metal-accumulative proteins with antioxidant potential metallothioneins (MT) in crucian carp (Carassius auratus gibelio) was studied­. Fish was subjected to the effect of Co-NC, Zn-NC, Co2+, Zn2+ or polymer carrier (PC) in the concentrations correspondent to 50 µg×Co/l or 100 µg×Zn/l during 14 days. It was shown that the MTs response is highly specific for the nature of metal, both in ion and Me-NC form: the effect of Co and Co-NC provoked the elevation of total MT concentration (MT-SH) and activation of antioxidant defence, whereas Zn and Zn-NC induced the decrease of the concentration of MT-SH and the inhibition of antioxidant defense. All the exposures provoked the decrease of the concentration of immunoreactive chelating MT form (MTi) and reduced glutathione, activation of anaerobiosys and Mn-superoxide dismutase, and also decrease of the concentration of proteins and lipids oxidative injury products. It was accompanied by the increase of the content of erythrocytes with nuclear abnormalities but did not cause the decrease of choline esterase activity. According to the rate of MT-SH and MTi concentrations, antioxidant potential of MTs is determined by its apoform. Our data indicate that partial biodegradation of Me-NC occurs in the organism of crucian carp.

Trace elements storage peculiarities and metallothionein content in human thyroid gland under iodine deficiency euthyroid nodular goiter

H. I. Falfushynska1,2, L. L. Gnatyshyna1, O. Osadchuk2, V. O. Shidlovski2, О. B. Stoliar1

1Ternopil Volodymyr Hnatiuk National Pedagogical University, Ukraine;
2I.Ya. Horbachevski Ternopil State Medical University, Ukraine;
e-mail: halynka.f@gmail.com

Accumulation of iodine and copper in the node, paranodular and contralateral (not affected tissue by node) tissues of thyroid gland in relation to the level of metal-binding proteins, potential antioxidants and oxidative changes in tissue was investigated. To assess the severity of the pathological process the molecular markers of cytotoxicity were used. The reduction of total iodine (by 19.5%), increase of inorganic iodine fraction (by 82.4%) and total copper content (twice) in paranodular and nodular tissues compared with contrlateral part have been established. Excess of copper in goitrous-changes tissue was partially accumulated in the metallothioneins. The level of metal-binding form of metallothioneins and reserve of free thiols of these proteins was higher two-three times and lower content of reduced glutathione in node-affected tissue compared to the contralateral part. Signs of cytotoxicity among them: higher cathepsine D free activity (up to 84.6% and 134.4% in paranodular tissue and node respectively) and higher level of DNA strand breaks in the node (up to 22.6%) were observed. In paranodular tissue the range of indices variability compared with parenchyma of contralateral part is shorter than in the node. Thus, under low level of iodine organification and high copper level in goitrous-modified tissue of thyroid gland metallothionein may provide a partial compensatory effect on prooxidative processes.