sodium-nitrite and cupric-chloride

The effects of bivalent ions on tubulin dynamics and the upper phase of glycolysis were investigated at different organization levels in vitro. Cu2+, Cd2+, Hg2+ and CrO4(2-) inhibit the tubulin polymerization at an IC50 of 14-24 microM with high cooperativity and also induce microtubule disassembly. The apparent binding constants of the ions to tubulin, estimated by fluorescence quenching, vary between 6 and 28 microM. BIAcore measurements for tubulin-tubulin interaction suggest that the presence of Cu2+ affects neither koff nor kon, but the amount of the bound tubulin. While the inhibitory effect of Cu2+ on tubulin polymerization is partially abolished by cross-linking of microtubules with substoichiometric amounts of phosphofructokinase or decoration of tubules with cytosolic proteins, in the presence of kinase but not with cytosolic proteins the tubules are resistant to CrO4(2-). No inhibitory effect of Cu2+ or CrO4(2-) on microtubule assembly was detected in the MAP-containing cytosolic fraction. Electron microscopy revealed that tubules assembled in the presence of Cu2+ or CrO4(2-) ions contain aggregates of thread-like oligomers that are less conspicuous in the presence of cytosolic proteins. Cu2+, Cd2+, and Hg2+ inhibit the glycolytic flux in the cytosolic fraction characterized at equilibrium by an IC50 of 10-14 microM with high cooperativity. Tubulin diminishes the inhibitory effect of the cations. These data indicate that the responses elicited by the bivalent ions are highly dependent on the supramolecular organization of the systems.

Topics: Acetates; Animals; Brain; Cadmium; Cattle; Chromates; Copper; Cytosol; Dose-Response Relationship, Drug; Glycolysis; Inhibitory Concentration 50; Ions; Kinetics; Mercury Compounds; Microscopy, Electron; Microtubules; Nitrates; Organometallic Compounds; Phosphofructokinase-1; Potassium Compounds; Protein Binding; Sodium Nitrite; Spectrometry, Fluorescence; Surface Plasmon Resonance; Time Factors

The study was performed on 4 groups of male Wistar rats, receiving p.o. through 3 months every day: 1) sodium nitrite in dose 30 mg/kg b.w. x day (0.2 LD50); 2) copper chloride in dose 4.67 mg/kg b.w. x day (0.03 LD50); 3) copper chloride and sodium nitrite in amounts as above, and 4 - control group - received distilled water. The methemoglobin and hemoglobin were determined in whole blood and tryptophan in plasma 24 hours after the last intoxication. There was showed, that every day intoxication of rats with sodium nitrite cause the increase of methemoglobin concentration and decrease the free tryptophan level in the blood. There was also observed, that copper chloride, administrated together with sodium nitrite, decreases significantly his methemoglobin creating action.

Topics: Animals; Copper; Drug Administration Schedule; Male; Methemoglobinemia; Rats; Rats, Wistar; Sodium Nitrite; Tryptophan

The study was performed on 4 groups of male Wistar rats, receiving p.o. through 3 months every day: 1). Sodium nitrite in dose 30 mg/kg b.w. x day (0.2 LD50); 2). Cupric chloride in dose 4.67 mg/kg b.w. x day (0.03 LD50); 3 ). Cupric chloride and sodium nitrite in amounts as above, and 4). Control group--received dest. water. The activity of alanine aminotransferase (AlAT), aspartate aminotransferase (AspAT), gamma-glutamyltransferase (GGTP-ase) and creatinine and urea level in blood plasma were determined 24 hours after the last application of compounds. There was showed, that every day rats' intoxication with sodium nitrate during 90 days caused the significant increase of gamma-glutamyltransferase activity and decrease of urea level in the blood plasma. Subchronic exposure to copper and copper with sodium nitrate causes no effect on biochemical parameters were studied.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Copper; Creatinine; Drug Interactions; gamma-Glutamyltransferase; Lethal Dose 50; Male; Rats; Rats, Wistar; Sodium Nitrite; Urea