The effect of lipoic acid on cyanate toxicity in the rat heart.

Background: Cyanate is a uremic toxin formed principally via spontaneous urea biodegradation. Its active isoform, isocyanate, is capable of reaction with proteins by N and S carbamoylation, which influences their structure and function. Sulfurtransferases implicated in anaerobic cysteine transformation and cyanide detoxification belong to the enzymes possessing SH groups in their active centers.

The effect of lipoic acid on cyanate toxicity in different structures of the rat brain.

Cyanate is formed mostly during nonenzymatic urea biodegradation. Its active form isocyanate reacts with protein -NH2 and -SH groups, which changes their structure and function. The present studies aimed to investigate the effect of cyanate on activity of the enzymes, which possess -SH groups in the active centers and are implicated in anaerobic cysteine transformation and cyanide detoxification, as well as on glutathione level and peroxidative processes in different brain structures of the rat: cortex, striatum, hippocampus, and substantia nigra.

The effect of the uremic toxin cyanate (CNO⁻) on anaerobic cysteine metabolism and oxidative processes in the rat liver: a protective effect of lipoate.

Chronic renal failure (CRF) patients have an increased plasma level of urea, which can be a source of cyanate. This compound can cause protein carbamoylation thereby changing biological activity of proteins. Therefore, in renal failure patients, cyanate can disturb metabolism and functioning of the liver.

The effect of uremic toxin cyanate (OCN–) on anaerobic sulfur metabolism and prooxidative processes in the rat kidney: a protective role of lipoate.

Cyanate and its active form isocyanate are formed mainly in the process of nonenzymatic urea biodegradation. Cyanate is capable of protein S- and N-carbamoylation, which can affect their activity. The present studies aimed to demonstrate the effect of cyanate on activity of the enzymes implicated in anaerobic cysteine metabolism and cyanide detoxification and on glutathione (GSH) level and peroxidative processes in the kidney.

Nephroprotective effect of cystathionine is due to its diverse action on the kidney and Ehrlich ascites tumor cells.

Tumor cells, unlike normal cells, are characterized by trace cystathionase (CST) activity and sulfane sulfur levels. The present studies aimed to established whether cystathionine (CT), a substrate of cystathionase, can selectively influence the thiol-dependent antioxidant power of the kidney and Ehrlich ascites tumor (EAT). CT treatment reversed the changes in renal concentrations of non-protein thiols (NPSH), reactive oxygen species (ROS), sulfane sulfur and activities of rhodanese, cystathionase and glutathione S-transferase (GST) in tumor-bearing mice, which returned to the level observed in healthy animals.

The effect of modulation of gamma-glutamyl transpeptidase and nitric oxide synthase activity on GSH homeostasis in HepG2 cells.

High glutathione (GSH) level and elevated gamma-glutamyl transpeptidase (gammaGT) activity are hallmarks of tumor cells. Toxicity of drugs and radiation to the cells is largely dependent on the level of thiols. In the present studies, we attempted to inhibit gammaGT activity in human hepatoblastoma (HepG2) cells to examine whether the administration of gammaGT inhibitors, acivicin (AC) and 1,2,3,4-tetrahydroisoquinoline (TIQ) influences cell proliferation and enhances cytostatic action of doxorubicin (DOX) and cisplatin (CP) on HepG2 cells.

[Infections caused by Shigella flexneri recognized as food poisonings in Warmia and Mazury Voivodeship].

This article treats of infections submitted as food poisoning examples caused by Shigella flexneri 3a which is an etiological factor of diseases characterized by different clinical picture. The aim of the research was to test our laboratory specific procedure in diagnostics of Shigella infections. The stool was inoculated on three following solid culture media: salmonella - Shigella Agar (SS), Mac Conkey Agar (MC), Hektoen Enteric Agar (HE) and one liquid medium selenite - phosphate medium (SF).

Treatment with 1,2,3,4-tetrahydroisoquinolone affects the levels of nitric oxide, S-nitrosothiols, glutathione and the enzymatic activity of gamma-glutamyl transpeptidase in the dopaminergic structures of rat brain.

Depletion of glutathione (GSH), nitrosative stress and chronic intoxication with some neurotoxins have been postulated to play a major role in the pathogenesis of Parkinson's disease. This study aimed to examine the effects of acute and chronic treatments with 1,2,3,4-tetrahydroisoquinoline (TIQ), an endo-/exogenous substance suspected of producing Parkinsonism in human, on the levels of nitric oxide (NO), S-nitrosothiols and glutathione (GSH) in the whole rat brain and in its dopaminergic structures. TIQ administered at a dose of 50 mg/kg i.

Bioactivation of nitroglycerin to nitric oxide (NO) and S-nitrosothiols in the rat liver and evaluation of the coexisting hypotensive effect.

The aim of the present study was to investigate nitroglycerin (NTG) bioactivation pathways in the liver after various periods of its administration. We also attempted to elucidate the relationship between nitric oxide (NO) and S-nitrosothiol (SNT) levels, and concentration of nonprotein thiols (NPSH) and intensity of peroxidative processes. Intravenous injections of NTG cause an increase in NO and SNT levels in the rat liver.

Activation of DNA biosynthesis in human hepatoblastoma HEPG2 cells by the nitric oxide donor, sodium nitroprusside.

The role of nitric oxide (NO) in carcinogenesis is controversial as it has been shown to both stimulate and inhibit tumour growth. Also, there are contradictory opinions regarding the effects of NO on the proliferation of normal and tumour cells. The aim of our study was to use an in vitro model to determine the influence of exogenous NO donors on DNA biosynthesis by measuring [3H] thymidine incorporation in human hepatoblastoma cells (HepG2).

Influence of N-acetylcysteine on bioactivation of nitroglycerin to nitric oxide and S-nitrosothiols in the liver and brain of mice.

Three-day nitroglycerin (NTG) administration at progressively increasing doses caused a drop in the liver S-nitrosothiol (SNT) and malonyldialdehyde (MDA) concentrations below the control levels. It suggests that NTG administered in this way, exhibits antioxidant activity due to releasing the biologically active SNT and nitric oxide (NO). On the other hand, in the brain, NTG did not influence SNT concentrations, but slightly elevated NO formation.

Inhibition of the catalytic activity of rhodanese by S-nitrosylation using nitric oxide donors.

Rhodanese (EC 2.8.1.

Alteration in plasma levels of nonprotein sulfhydryl compounds and S-nitrosothiols in chronic renal failure patients.

Background: Uremia is accompanied by the elevated nitric oxide (NO) synthesis, and it has not yet been established how this influences the levels of nonprotein sulfhydryl compounds (NPSH) and formation of S-nitrosothiols (SNT).

Methods: Our study was designed to determine plasma levels of SNT and NPSH in chronic renal failure (CRF) patients, who were hemodialysed (HD) or were not on hemodialysis treatment (ND), and in the control group.

Results: In ND patients, the plasma levels of SNT were significantly increased (11.

The gamma-glutamyltransferase activity and non-protein sulfhydryl compounds levels in rat kidney of different age groups.

The present work was aimed to obtain information about age-dependent changes of gamma-glutamyltransferase (GGT) activity and the levels of non-protein sulfhydryl compounds (NPSH) in rat kidneys. In addition, protein-bound cysteine (PB-Cys), sulfane sulfur compounds and reactive oxygen species (ROS) were estimated. The results indicate that the activity of GGT and NPSH levels in the kidneys are reduced with age.