In comparison with the actions of other biologically active substances, ginsenosides, obtained from ginseng, have a nootropic spectrum of pharmacological activity, including improvements in memory fixation, antihypoxic actions, increases in the resistance of the central nervous system to damage due to trauma, electric shock, and toxic substances. The effects of ginseng (in the form of a total extract) on higher nervous activity have been studied in some detail [4]. Administration of ginseng shortened the latent period of a conditioned positive escape response, improving the processes of differentiation of both positive and negative conditioned stimuli. Ginseng also produced significant increases in attention in rats [2]. A new stage in the study of the central effects of ginseng consisted of analysis of separate' fractions and individual ginsenosides. Studies in humans and animal experiments both showed that systemic administration of ginseng or its individual saponins could have effects on "undamaged memory" and on the learning process [1]. However, no data have been published on the efficacy of ginseng polysaccharides. The aim of the present work was to study the effects of courses of systemic administration of a polysaccharide fraction of ginseng extract on the formation of an active escape response in rats in a shuttle box.Experiments were carried out using adult male Wistar rats (n = 70) of weight 230-270 g. Animals were kept in standard conditions and received a balanced diet; illumination was provided from 8:30 to 20:30, and consisted of a combination of artificial and natural light sources. A polysaccharide fraction (PSF) of red Korean ginseng (Panax ginseng, C. A. Meyer) was obtained from the Korean Institute of Tobacco and Ginseng (Tedzhon). Doses of 1, 5, and 10 mg per animal were given i.p., corresponding to 4, 20, and 40 mg/kg. Courses lasted 10 days. Before each injection, aliquots of PSF were dissolved in several drops of 70% ethanol (the same quantity of ethanol was added to physiological saline for controls), and the required volume was made up with sterile physiological saline. The preparation was given 30 rain before testing in a shuttle box, on days 8 and 10 of courses of ginseng polysaccharides. Oxytocin (Serva) was given at a dose of 10 gg per animal 10 min before testing.A conditioned active escape response (CAER) was developed in the shuttle box using a completely computerized apparatus from Omnitech Electronics Inc. (USA). Training was carried out giving the rat a one-sided escape route, using stimuli with a constantly varying aversive gradient; this is known to make learning of the CAER more difficult, requiring a significant number of repeats for successful completion of the task. During training of the CAER in different groups of animals, two regimes of presentation were used: "easy" and "hard."In the "easy" regime (n = 25), the conditioned signal (CS, a sound lasting 5 sec) was followed immediately by the unconditioned signal (US, an electric shock of 0.5-1.0 mA lasting 10 sec). The...
A method for adsorption chromatography of proteins is proposed. A protein solution is passed through a cellulose column at a pH value corresponding to an isoelectric point of the protein. Depending on the charge of unwanted proteins, they either remain at the origin (if charges of protein and ion-exchanger are opposite) or are released from the column (if charges of protein and ion-exchanger coincide). Elution volume of the purified protein is higher than for the second group of unwanted proteins because movement of the uncharged protein of interest includes its adsorption on cellulose followed by subsequent desorption caused by the elution buffer. Problems of optimization of buffers and adsorbents are discussed. Applicability of the method of adsorption chromatography is illustrated using purification of horseradish peroxidase as an example.
Yersinia pseudotuberculosis, Brucella abortus, and Francisella tularensis strains producing a recombinant [3-endorphin have been obtained. The highest production of this peptide, which displays physiological activity, was recorded for cells of the Y. pseudotuberculosis strain 2243 (pSK95E).Key Words: ~-endorphin; producer strains; synthesis; biological activityIn our previous study [2], in which the regulatory peptide [~-endorphin additively synthesized by a microbial donor was evaluated for its influence on the physiological state of recipient organisms, we established that the psychoemotional status and nociceptive responses of CBA mice depend on the reproductive dynamics in these hosts of the Francisella tularensis strain generating a recombinant l~-endorphin. The prolonged effect induced by this strain exceeded by 25-50% the mean index of pain sensitivity inhibition [15]. Native ~-endorphin (8-10 gg/kg) elicited in mice only a short-term effect that varied from 0 to 200-300% [2].In an. effort to further boost the additive action of recombinant [~-endorphin, we have now explored the possibility of producing a number of strains capable of more intensive and more prolonged synthesis of this peptide in vitro and in the vaccinated animal host.With this aim in view, we selected known vaccine strains of Brucella abortus and Francisella tularensis as well as avirulent Yersinia pseudotuberculosis strains. These microorganisms are all capable
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