ABSTRACT
The influence of hypoxia on nitric oxide formation in the blood of Krushinskii-Molodkina rats has been studied by electron paramagnetic resonance. It was found that nitric oxide synthesis in Krushinskii-Molodkina rats is increased compared with that in Wistar rats. A significant enhancement of the EPR signal of Hb-NO complexes in the animal blood was observed after hypoxia simulating the altitude of 5000 m above the sea level, in particular in the presence of sodium nitrite and the NO-synthase inhibitor L-nitroarginine. It was assumed that NO synthesis and nitro-/nitrite- reductase systems are activated under hypoxic conditions.
Subject(s)
Hemoglobins/metabolism , Hypoxia/blood , Nitric Oxide/blood , Animals , Electron Spin Resonance Spectroscopy/methods , Hemoglobins/analysis , Male , Rats , Rats, Wistar , Species SpecificityABSTRACT
A possible involvement of nitric oxide in the protective effect of short-term adaptation of Krushinsky-Molodkina rats to mild hypoxia simulating 5000 m above sea level was studied. Nitric oxide proved to have a considerable protective effect on stress-induced disorders in Krushinsky-Molodkina rats as demonstrated using NO-synthase inhibitors and NO monitoring by electron spin resonance under different experimental conditions.
Subject(s)
Adaptation, Physiological/physiology , Enzyme Inhibitors/pharmacology , Hypoxia/metabolism , Nitric Oxide Synthase/antagonists & inhibitors , Nitric Oxide/metabolism , Adaptation, Physiological/drug effects , Animals , Electron Spin Resonance Spectroscopy , Hypoxia/prevention & control , Male , Nitric Oxide Synthase/metabolism , Rats , Stress, Physiological/metabolism , Stress, Physiological/prevention & controlABSTRACT
The method of magnetic neutron capture therapy (MNTC) of cancer can be described as a combination of two methods: the targeted delivery of drugs using magnetic carriers and the proper neutron capture therapy which consists in tumor irradiation with thermal neutrons following the delivery of 10B compounds to the tumor site. Two-component ultradispersed particles containing Fe and C were tested as magnetic adsorbents of boron phenylalanine and borax. The quantities of absorbed borax proved sufficient for high concentration of boron atoms at the tumor site. The kinetics of boron release to saline substantiates the application of Fe-B (10%) ultradispersed particles for efficient MNTC. Both particle types have high magnetization and magnetic homogeneity, can form stable magnetic suspensions, and have low toxicity.
Subject(s)
Boron Compounds/toxicity , Boron Neutron Capture Therapy , Nanostructures/toxicity , Neoplasms/radiotherapy , Neutrons/therapeutic use , Animals , Boron Compounds/chemical synthesis , Boron Neutron Capture Therapy/adverse effects , Boron Neutron Capture Therapy/methods , Humans , Male , Mice , Mice, Inbred BALB C , Nanostructures/chemistry , Neoplasms/pathologyABSTRACT
Kinetic parameters of the hemin spectral alterations occurred in reactions with sodium thiosulfate and sodium dithionite were studied depending on the reagents content as well as on the ratio between the antioxidant initial concentration and hemin. Simultaneous analysis of the kinetic parameters enabled one to suggest that hemin was reduced in reactions with sodium thiosulfate and sodium dithionite.
Subject(s)
Antioxidants/chemistry , Hemin/chemistry , Kinetics , Oxidation-Reduction , Spectrum AnalysisABSTRACT
Effect of nitrite ions on content of proteins (hemoglobin, albumin and others), peptides (AKTH and endothelin-1, 2) of total alpha-aminonitrogen and cGMP was studied in rat blood. The data obtained suggest that NO2- may be involved in regulation of these physiologically active substances because NO2- are the deposited form of nitric oxide which may regulate the inter- and intracellular signal systems.
Subject(s)
Nitrites/metabolism , Signal Transduction , Animals , Anions , Blood Proteins/metabolism , Cyclic GMP/metabolism , Male , Nitric Oxide/physiology , Peptides/metabolism , RatsABSTRACT
Concentration of blood proteins, alpha-amino nitrogen, cGMP and endothelin-1,2 was studied in rat's blood at nitric hypoxia. The injection of NaNO2 (5 mg/100 g body weight) was followed by decrease in total protein, albumin and hemoglobin content and by sharp increase in methemoglobin and Hb-NO complexes concentration in rat's blood. Simultaneously, the elevation of free amino acids and peptides with m.w. 2500 D in blood was discovered. One of these peptides was the endothelin-1,2, whose concentration increased twice in plasma at nitric hypoxia. The increase in endothelin and cGMP concentrations is mostly linked with activation of compensative mechanisms, arising as a response to high concentrations of nitro compounds and NO in rats.
