Pro-oxidative, genotoxic and cytotoxic properties of uranyl ions.

It is demonstrated that hydroxyl radicals and hydrogen peroxide are formed under the action of uranyl ions in aqueous solutions containing no reducing agents. In the presence of uranyl ions, formation of 8-oxoguanine in DNA and long-lived protein radicals are observed in vitro. It is shown that the pro-oxidant properties of uranyl at micromolar concentrations mostly result from the physico-chemical nature of the compound rather than its radioactive decay. Uranyl ions lead to damage in DNA and proteins causing death of HEp-2 cells by necrotic pathway. It is revealed that the uranyl ions enhance radiation-induced oxidative stress and significantly increase a death rate of mice exposed to sublethal doses of X-rays.

[The characteristics of the anxiolytic action of benzodiazepine and non-benzodiazepine tranquilizers in different tests of anxiety]. / Osobennosti anksioliticheskogo deistviia benzodiazepinovykh i nebenzodiazepinovykh trankvilizatorov na razlichnykh testakh trevogi.

In experiments on rats the presence or absence was studied of the phenomenon of potentiation of anxiolytic action, estimated by the time of the animal stay in the light part of the chamber in tests of avoidance of "the lighted ground" or "menacing situation" at combined application of the pairs of substances of benzodiasepine and non-benzodiasepine series (elenium, indoter, campiron and campironin). Spectra of their neurochemical activity were determined in experiments on neurones of isolated spinal ganglia of rats with intracellular biopotentials records. It has been established that GABA-potentiating action of indoter and elenium, dopamine-negative action of campiron and campironin are significant in their anxiolytic action in the states of alarm of aversive genesis of different modalities. Serotoninmimetic effect of non-diasepine tranquilizers is of functional significance in the test of avoidance of "the lighted ground", but not of the "menacing situation". It is suggested that differences of neurochemical mechanisms of anxiolytic action of the tested tranquilizers testify to different neurochemical profiles of the neuronal "matrices" of the studied states of alarm.