An Experimental Study of the Pharmacokinetics of the Antitumor Drug Aurumacryl

The distribution of the antitumor drug aurumacryl (intraperitoneally injected at a dose of 100 mg/kg) in the bodies of animals with Lewis lung carcinoma was studied. The determination of aurumacryl in the tumors and organs (blood, liver, kidneys, lungs, spleen, and brain) of mice was carried out for 48 h by measuring the gold content in the test tissues using inductively coupled plasma mass spectrometry. We found the preferential accumulation of the drug in the kidneys with an extremely low gold content in the brain and a relatively uniform distribution of aurumacryl between the tumor, liver, lung, and spleen tissues.

     

Subcellular distribution and several properties of the cAMP enzyme system of phototrophic bacteria]

In the cells of the phototrophic bacteria Rhodospirillum rubrum and Rhodopseudomonas palustris the two enzymes of the cAMP system enzymes - adenylate cyclase and cAMP phosphodiesterase (PDE) exist in a soluble and membrane-bound forms. After mild disruption of the cells (sonication up to 3 min) the activity of both enzymes is found in the chromatophores. In the cells of the two types of bacteria grown under anaerobic conditions soluble adenylate cyclase is predominant. In the cells of R. rubrum the soluble form of PDE posesses higher activity, whereas in the cells of Rh. palustris a higher activity is observed in the membrane-bound form. In addition to their different localization in the cells, the PDE forms of Rh. rubrum differ in their ratios to the concentrations of hydrogen ions and bivalent metals; the latter difference, however, may be accounted for by the effect of a protein modulator of PDE. The pH optimum of membrane-bound PDE is 9.15. Soluble PDE has two activity maxima at pH 7.5 and 8.7. It is probable that similar to the animal tissue enzyme, PDE from Rh. rubrum exists in the soluble phase in at least tw forms. Close pH optima for soluble adenylate cyclase and for one of the soluble PDE forms (about 8.5) may indicate the unidirectional control of these enzymes by hydrogen ion concentration.     

Changes in the expression of receptors of steroid hormones in the development of partial androgen deficiency of aging men (PADAM)

This work is devoted to the vital topic of the influence of partial androgen deficiency of aging men (PADAM) on the development of cells with androgen receptors. The results obtained in this study suggest a conclusion that the production of testosterone by some tumors and tissues of the peritumorous zone, which is accompanied by increased proliferative activity and disturbance of the regulation of the cell cycle, is caused by PADAM. The given changes are directed at compensating for testicular deficiency (in particular at overcoming the androgen-dependent stage of development of androgen-sensitive cells). These changes are a partial manifestation of metabolic syndrome (X-syndrome). The atypical cells, which unavoidably develop during metabolic syndrome, are dealt with by means of the immune system, whose capabilities become less and less adequate in the given circumstances.     

Experimental estimation of the effect of antibiotics, immobilized on the surface of titanium implant, on the development of the inflammatory process

Titanium implants with immobilized lincomycin and ampicillin were studied on rats with respect to the effect on development of inflammatory reactions. The data on the concentrations of sialic acids in the blood during the postoperative period and the histological examinations showed that lower concentrations of sialic acids, early fibroblastic reaction, productive nature of inflammation in the main and rapid formation of the fibrous connective tissue capsule around the implants were the characteristic features and advantages of the use of the implants with the immobilized antibiotics as compared to the use of the routine titanium implants.     

Purification, Properties, and Localization of Two Carbonic Anhydrases from Amaranthus cruentus Leaves

The method has been developed for obtaining two purified forms of carbonic anhydrase (CA, A and B forms) from amaranth (Amaranthus cruentus L.) leaves. The method includes precipitation with ammonium sulfate, fractionation by ion-exchange chromatography on DEAE Sephadex A-50, gel filtration on AcA-34 ultragel, and ion-exchange chromatography on DEAE cellulose. The molecular weights of A and B forms were different and equaled to 151 and 251 kD, respectively. The results suggest that SH groups and zinc play important roles in the catalytic activity of both CA forms. Both forms exhibited a high hydratase activity and did not represent allosteric enzymes. However, the catalytic properties of A form, evaluated from the pH dependence of kinetic parameters, differed from those of B form, which was apparently caused by dissimilar structures of these forms. Furthermore, the A form was localized in chloroplast membranes of bundle sheath cells, whereas B form was a soluble enzyme located in the cytoplasm of mesophyll cells.     

cAMP phosphodiesterase from phototrophic bacteria Rhodospirillum rubrum]

cAMP phosphodiesterase activity is discovered in supernatant of R. rubrum cell homogenate after centrifugation at 1000 g. The enzyme is highly active (5.62 nmoles/mg of protein per 1 min) at a broad pH range--from 7.0 to 9.0. The enzyme activity is strongly inhibited with caffeine and dithiotreitol and very significantly inhibited by ascorbic acid. The dependence of the enzyme activity on the incubation time and protein and substrate concentrations in the reaction mixture is estimated. cAMP phosphodiesterase is found in soluble fraction and in particule fractions sedimenting at 30 000 g. The enzyme activity is completely absent in washed chromatophores sedimenting at 160 000 g.     

Effect of growth conditions on the activity of the enzymes of cyclic 3':5'-AMP synthesis and decay in phototrophic bacteria]

Activity, ratio and summary content of cyclic AMP enzymes, adenylate cyclase and phosphodiesterase varied depending on growth conditions of phototrophic bacteria (Rhodospirillum rubrum and Rhodopseudomonas palustris). It suggests, that membrane-bound and soluble enzymes carry different functions. The increase of adenylate cyclase under chaning growth conditions was usually accompanied by the increase of phosphodiesterase. Sharp increase of both enzymes activity was observed when bacteria were growth in aerobic conditions. The activity of both enzymes in chromatophores was 2.8-fold higher when bacteria were grown in the light in anaerobic conditions, than in chromatophores of bacteria grown under stationary aerobic conditions in the light. It is suggested that 3':5' AMP can participate in autotrophic carbon assimilation or in the synthesis of pigments and other components of bacterial photosynthetizing apparatus. Substitution of NH4+ into NO3- and glutamate under the growing of R. rubrum in anaerobic conditions in the light resulted in the increase of the enzymes activities, which is the evidence of possible role of 3':5' AMP in mineral nitrogen uptake and nitrogen fixation. Glutamate concentration of 4 g/l stimulated the enzymes both in vivo and in vitro. The data obtained suggest that 3':5' AMP can carry multiple functions, participating in regulation of a number of metabolic processes in photorophic bacteria.