scholarly journals A role of metallothionein in zinc regulation after oestradiol induction of vitellogenin synthesis in rainbow trout, Salmo gairdneri

1989 ◽  
Vol 257 (2) ◽  
pp. 555-559 ◽  
Author(s):  
P E Olsson ◽  
M Zafarullah ◽  
L Gedamu
Keyword(s):  
Rainbow Trout ◽  
Experimental Period ◽  
Differential Pulse ◽  
Salmo Gairdneri ◽  
Differential Pulse Polarography ◽  
Pulse Polarography ◽  
Vitellogenin Synthesis ◽  
Zinc Concentrations ◽  
Liver Somatic Index ◽  
Vitellogenin Mrna

The regulation of metallothionein (MT) biosynthesis in rainbow-trout liver was studied after a single intraperitoneal injection of oestradiol-17 beta. Sampling was performed after 2, 7, 14, 21, 28 and 35 days. Following induction of vitellogenin synthesis in the liver, liver somatic index (LSI) rose from 1.25 to 2.00 in 14 days. Associated with the increase in LSI was an elevation of hepatic vitellogenin mRNA and zinc concentrations. The vitellogenin mRNA concentrations peaked at 7 days after treatment. The zinc concentrations increased to a peak at day 14. MT was analysed by using differential pulse polarography and a rainbow-trout MT RNA probe. The MT mRNA concentrations rose after 14 days and remained elevated at 21 and 28 days. The MT concentrations increased after 14 days and remained elevated throughout the experimental period. The concentrations of MT-bound zinc increased in association with the elevation in MT concentrations in the oestradiol-treated rainbow trout. These findings indicate that MT is involved in the regulation of zinc during the period of vitellogenin induction and that MT may function by maintaining the pool of available zinc at an appropriate concentration.

scholarly journals Interaction of cadmium and oestradiol-17β on metallothionein and vitellogenin synthesis in rainbow trout (Oncorhynchus mykiss)

1995 ◽  
Vol 307 (1) ◽  
pp. 197-203 ◽  
Author(s):  
P E Olsson ◽  
P Kling ◽  
C Petterson ◽  
C Silversand
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Intraperitoneal Injection ◽  
High Molecular Mass ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Vitellogenin Synthesis ◽  
Liver Somatic Index ◽  
Somatic Index ◽  
Rainbow Trout Liver ◽  
Vitellogenin Mrna

The induction of metallothionein and vitellogenin synthesis in rainbow trout liver was studied after injection of oestradiol-17 beta alone or in combination with cadmium or zinc. Intraperitoneal injection of oestradiol-17 beta increased the liver somatic index, with subsequent induction of vitellogenin synthesis. Oestradiol-17 beta did not induce metallothionein synthesis. Injection of cadmium induced the synthesis of metallothionein mRNA and metallothionein. Injection of oestradiol-17 beta in combination with cadmium resulted in inhibition of transcription and translation of both vitellogenin and metallothionein. Chromatography of liver cytosols revealed that cadmium, when co-injected with oestradiol-17 beta, did not bind to metallothionein but would initially bind to high-molecular-mass (HMr) cytosolic proteins. In fish injected with cadmium in combination with oestradiol-17 beta, cadmium was gradually redistributed from HMr proteins to metallothionein. This resulted in induction of metallothionein synthesis and in binding of most of the cadmium to metallothionein. Induction of vitellogenin mRNA was observed 15 days after injection, as cadmium was being redistributed to newly synthesized metallothionein. These findings indicate that cadmium inhibits the transcription of vitellogenin. The binding of cadmium to these non-metallothionein proteins represses the induction of metallothionein and results in increased toxicity of the metal. Preinduction of metallothionein by zinc injections resulted in decreased cadmium sensitivity of the fish and a decrease in the repression of vitellogenin mRNA. Furthermore, a role for metallothionein in the detoxification of cadmium is indicated by the induction of vitellogenin synthesis that occurs once metallothionein has begun sequestering cadmium.

Determination of platinum in biological material by differential pulse polarography: Analysis in urine, plasma and tissue following sample combustion

1983 ◽  
Vol 48 (10) ◽  
pp. 2903-2908 ◽  
Author(s):  
Viktor Vrabec ◽  
Oldřich Vrána ◽  
Vladimír Kleinwächter
Keyword(s):  
Biological Material ◽  
Biological Fluid ◽  
Mercury Electrode ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Linear Calibration ◽  
Catalytic Current ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode

A method is described for determining total platinum content in urine, blood plasma and tissues of patients or experimental animals receiving cis-dichlorodiamineplatinum(II). The method is based on drying and combustion of the biological material in a muffle furnace. The product of the combustion is dissolved successively in aqua regia, hydrochloric acid and ethylenediamine. The resulting platinum-ethylenediamine complex yields a catalytic current at a dropping mercury electrode allowing to determine platinum by differential pulse polarography. Platinum levels of c. 50-1 000 ng per ml of the biological fluid or per 0.5 g of a tissue can readily be analyzed with a linear calibration.

Polarography of N,N-dimethyl-4-amino-4'-hydroxyazobenzene in water-methanol mixtures

1985 ◽  
Vol 50 (3) ◽  
pp. 712-725 ◽  
Author(s):  
Jiří Barek ◽  
Lubomír Kelnar
Keyword(s):  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Polarographic Reduction ◽  
Reduction Mechanism ◽  
Pulse Polarography ◽  
Methanol Medium

The polarographic reduction of N,N-dimethyl-4-amino-4'-hydroxyazobenzene in water-methanol medium was investigated. Evidence is presented for adsorption of the depolarizer on the electrode, and a reduction mechanism is proposed. Conditions are indicated for the determination of this compound in the concentration range 10-4-10-6 mol/l by d.c. polarography, 10-5 to 3 . 10-7 mol/l by Tast polarography, and 10-5-3 . 10-8 mol/l by differential pulse polarography.

Polarographic and voltammetric determination of 6-mercaptopurine and 6-thioguanine

1986 ◽  
Vol 51 (11) ◽  
pp. 2466-2472 ◽  
Author(s):  
Jiří Barek ◽  
Antonín Berka ◽  
Ludmila Dempírová ◽  
Jiří Zima
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Detection Limits ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Pulse Voltammetry

Conditions were found for the determination of 6-mercaptopurine (I) and 6-thioguanine (II) by TAST polarography, differential pulse polarography and fast-scan differential pulse voltammetry at a hanging mercury drop electrode. The detection limits were 10-6, 8 . 10-8, and 6 . 10-8 mol l-1, respectively. A further lowering of the detection limit to 2 . 10-8 mol l-1 was attained by preliminary accumulation of the determined substances at the surface of a hanging mercury drop.

The polarographic and voltammetric determination of 2,6-dicyano-4-nitro-2'-acetylamino-4'-diethylaminoazobenzene

1990 ◽  
Vol 55 (6) ◽  
pp. 1508-1517 ◽  
Author(s):  
Jiří Barek ◽  
Dagmar Civišová ◽  
Ashutosh Ghosh ◽  
Jiří Zima
Keyword(s):  
Azo Dye ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Determination Limit ◽  
Polarographic Reduction ◽  
Hanging Mercury Drop Electrode ◽  
Optimal Conditions ◽  
Pulse Polarography ◽  
Pulse Voltammetry

The polarographic reduction of the title azo dye was studied and optimal conditions were found for its analytical utilization in the concentration range 1 . 10-6 - 1 . 10-7 mol l-1 using differential pulse polarography and 1 . 10-6 - 1 . 10-8 mol l-1 using fast scan differential pulse voltammetry or linear scan voltammetry at a hanging mercury drop electrode. When the latter technique is combined with adsorptive accumulation of the studied substance on the surface of the hanging mercury drop, the determination limit can be further decreased to 3 . 10-9 mol l-1.

Polarographic and voltammetric determination of N,N’-dinitrosopiperazine

1991 ◽  
Vol 56 (7) ◽  
pp. 1434-1445 ◽  
Author(s):  
Jiří Barek ◽  
Ivana Švagrová ◽  
Jiří Zima
Keyword(s):  
Mercury Electrode ◽  
Linear Sweep Voltammetry ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Polarographic Reduction ◽  
Concentration Region ◽  
Pulse Polarography ◽  
Chemical Efficiency ◽  
Dropping Mercury Electrode

Polarographic reduction of the genotoxic N,N’-dinitrosopiperazine was studied and its mechanism was suggested. Optimum conditions were established for the determination of this substance by tast polarography over the concentration region of 1 . 10-3 to 1 . 10-6 mol l-1 and by differential pulse polarography on the conventional dropping mercury electrode or by fast scan differential pulse voltammetry and linear sweep voltammetry on a hanging mercury drop electrode over the concentration region of 1 . 10-3 to 1 . 10-7 mol l-1. Attempts at increasing further the sensitivity via adsorptive accumulation of the analyte on the surface of the hanging mercury drop failed. The methods are applicable to the testing of the chemical efficiency of destruction of the title chemical carcinogen based on its oxidation with potassium permanganate in acid solution.

Determination of Organic Bases by Ion-Pair Extraction Polarography Using Orange II as Counter Ion

1992 ◽  
Vol 57 (11) ◽  
pp. 2272-2278 ◽  
Author(s):  
Václav Koula ◽  
Daria Kučová ◽  
Jiří Gasparič
Keyword(s):  
Model Compound ◽  
Differential Pulse ◽  
Ion Pair ◽  
Differential Pulse Polarography ◽  
Orange Ii ◽  
Organic Bases ◽  
Counter Ion ◽  
Pulse Polarography ◽  
Ammonium Compounds

The combination of ion-pair extraction and differential pulse polarography is shown to be a method suitable for the determination of 10-7 mol l-1 concentrations of organic bases of quaternary ammonium compounds. Orange II (4-[2-hydroxy-1-naphtyl]azobenzenesulfonic acid) was found to be an appropriate polarographically active counter-ion. The proposed method was used for the determination of tetrapentylammonium bromide (as model compound), Septonex ([1-(ethoxycarbonyl)-pentadecyl]trimethylammonium bromide) and codeine.

Polarographic Determination of 6-β-D-Glucopyranosyloxy-7-hydroxycoumarin

1996 ◽  
Vol 61 (3) ◽  
pp. 333-341
Author(s):  
Jiří Barek ◽  
Roman Hrnčíř ◽  
Josino C. Moreira ◽  
Jiří Zima
Keyword(s):  
Natural Compound ◽  
Mercury Electrode ◽  
Direct Determination ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Whitening Agent ◽  
Polarographic Behaviour ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode

The polarographic behaviour was studied for 6-β-D-glucopyranosyloxy-7-hydroxycoumarin, a natural compound serving as an optical whitening agent. The substance can be quantitated by tast polarography, differential pulse polarography using a conventional dropping mercury electrode, and differential pulse polarography using a static mercury drop electrode over the regions of 20-1 000, 2-1 000, and 0.2-1 000 μmol l-1, respectively. The methods developed for the quantitation of the compound were applied to its direct determination in a raw product.

Polarographic and Voltammetric Determination of Trace Amounts of 3-Nitrofluoranthene

2006 ◽  
Vol 71 (11-12) ◽  
pp. 1571-1587 ◽  
Author(s):  
Karel Čížek ◽  
Jiří Barek ◽  
Jiří Zima
Keyword(s):  
River Water ◽  
Solid Phase ◽  
Mercury Electrode ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode ◽  
Separation And Preconcentration

The polarographic behavior of 3-nitrofluoranthene was investigated by DC tast polarography (DCTP) and differential pulse polarography (DPP), both at a dropping mercury electrode, differential pulse voltammetry (DPV) and adsorptive stripping voltammetry (AdSV), both at a hanging mercury drop electrode. Optimum conditions have been found for its determination by the given methods in the concentration ranges of 1 × 10-6-1 × 10-4 mol l-1 (DCTP), 1 × 10-7-1 × 10-4 mol l-1 (DPP), 1 × 10-8-1 × 10-6 mol l-1 (DPV) and 1 × 10-9-1 × 10-7 mol l-1 (AdSV), respectively. Practical applicability of these techniques was demonstrated on the determination of 3-nitrofluoranthene in drinking and river water after its preliminary separation and preconcentration using liquid-liquid and solid phase extraction with the limits of determination 4 × 10-10 mol l-1 (drinking water) and 2 × 10-9 mol l-1 (river water).

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