[Structural changes in membranes of proliferating leukocytes L-41 as affected by low doses of ionizing radiation]. / Strukturnye izmeneniia v membranakh proliferiruiushchikh leikotsitov L-41 pod deistviem nizkikh doz ioniziruiushchego izlucheniia.

The dose-dependent effects of gamma-radiation on the leucocyte cultures L-41 has been investigated. Irradiation by the dose of 0.25 Gy stimulates the cell proliferation while that by the doses of 1.0 and 2.0 Gy inhibits this process. In this dose range the radiohormesis effects characterizing structural organization of the probed membranes have been also registered for fluorescence parameters. The zone of qualitative transition of response of the cell membranes to radiation is individual for various effects. The action of radiation in the doses of 0.25 and 0.50 Gy induces a decrease of ANS fluorescence intensity and a decrease of membrane protein immersion in the lipid bilayer of leukocyte membranes. The values of these parameters rise at the doses of 1.0 and 2.0 Gy that reflects different directions of structural changes in various membrane regions. The irradiation in the range of 0.25-1.0 Gy induces the increase of microviscosity in deep regions of membrane lipid matrix while at the dose 2.0 Gy it causes its decrease. Radioactive radiation does not change the membrane protein conformation of leukocytes and polarity of lipid bilayer hydrophobic zones as recorded by fluorescent methods used.

[Molecular mechanisms of damage to fractionated liver chromatin by tetrachloromethane]. / Molekuliarnye mekhanizmy povrezhdeniia fraktsionirovannogo khromatina pecheni tetrakhlormetanom.

Impairing effects of tetrachloromethane on genetic apparatus were shown to consist in its high affinity and binding to transcriptionally active fraction of chromatin and subsequent destruction of DNA. As a result of the impairment the density of the chromatin fraction was increased which expressed as elevated stability to hydrolysis by endogenous nucleases. At the same time, content of single-stranded structures enriched with proteins was increased in the DNA of the transcriptionally active fraction of chromatin. Two dissimilar properties were detected in the fraction of impaired chromatin from the poisoned animals: increase of density in the chromatin fraction accompanied by insensitivity to S1-nuclease, which was detected after denaturation of chromatin and slight relaxation of apparently supernucleosome structures where content of sites, sensitive to short-term treatment with DNAase I, was increased. The hypothesis of the tetrachloromethane toxic effect on genetic apparatus is considered, according to which lipid moiety of chromatin and activation of lipid peroxidation are of definite importance in effects of the xenobiotic on chromatin.

[The biochemical antagonism of cholinolytics and cholinomimetics at the level of the opiate system]. / Biokhimicheskii antagonizm kholinolitikov i kholinomimetikov na urovne opiatnoi sistemy.

The experiments on albino rats with the use of the radioimmunoassay showed that M-cholinoblockers (atropine, amizil, glypine) decrease the contents of enkephalins and beta-endorphin in the brain and blood whereas M-cholinomimetics (arecoline, nicotine, physostigmine) increase the level of opioid neuropeptides. This suggested that between cholinoblockers and cholinomimetics there is not only functional but also biochemical antagonism at the level of the opiate system. In addition, the statement is developed that toxic effects of cholinoblockers and cholinomimetics are largely related to disturbances of metabolism and function of opioid neuropeptides.

[Effect of central cholinolytics on opioid neuropeptide levels in the animal brain]. / Vliianie tsentral'nykh kholinolitikov na soderzhanie opioidnykh neiropeptidov v mozgu zhivotnykh.

Atropin, amizyl, glypin are shown to decrease the level of methionine- and leucin-enkefalins in the rat brain. The effect depends on the dose of cholinolytics.

[Isolation of opioid neuropeptides from the brain and blood and their quantitative determination by a radioimmunological method]. / Vydelenie opioidnykh neiropeptidov iz mozga i krovi i ikh kolichestvennoe opredelenie radioimmunologicheskim metodom.

The content of beta-endorphin, methionine- and leucine-enkephalins was determined in the brain and blood of albino mongrel rats. The unified scheme is suggested for releasing opioid neuropeptides from the brain tissue and blood.