[Potentiation of the radiosensitizing effect of metronidazole using whole-body drug-induced hyperthermia]. / Usilenie radiosensibiliziruiushchego éffekta metronidazola pri pomoshchi obshchei medikamentoznom gipertermii.

The total drug hyperthermia in the presence of metronidazole administration improves radiotherapeutic results in Pliss lymphosarcoma: tumor growth inhibition increases by 12.7-18.5%, tumor regression by 30.6-38.9%. A dose of 100 mg/kg of metronidazole combined with irradiation in the presence of moderate hyperthermia produces even a more noticeable radiosensitizing effect than a dose of 700 mg/kg without hyperthermia. A possibility of quite a high level of tumor radiosensitization with lower doses of metronidazole without toxic manifestations of the body was shown.

[Accumulation of metronidazole in tumors during whole-body hyperthermia induced by Sulfazin]. / Nakoplenie metronidazola v opukholi pri obshchei gipertermii, vyzvannoi sul'fazinom.

A study was made of metronidazole accumulation in the blood of animals and tumorous tissues of Pliss lymphosarcoma after the total moderate hyperthermia caused by subcutaneous injection of the pyrogenic drug sulfadiazine. Metronidazole concentration in the blood and tumors of hyperthermized animals was 2-3 times as high as in those of the control animals. A time shift of the maximum values of metronidazole accumulation occurred in hyperthermia. Under normal conditions the peak of accumulation was observed 2 h after the administration of the radiosensitizer whereas in hyperthermia depending on its duration it could develop 1 h earlier. Thus the total moderate hyperthermia served as a favorable background for raising metronidazole concentration in tumor opening up prospects for potentiating the radiosensitizing effect of metronidazole and perhaps some other means in the utilization of small nontoxic doses of the drug.

[Circadian rhythm of adenosine triphosphatase activity and 32P content in Pliss lymphosarcoma]. / Sutochnyi ritm aktivnosti adenozintrifosfataz i soderzhaniia 32P v limfosarkome Plissa.

Within a daily period maximal activity of ATPases and content of 32P in Pliss lymphosarcoma tissue was found in the samples taken at 15 or 21 p.m. and 3 a.m. The radioactivity in the tumor was minimal between 9 and 12 a.m. and 18 or 24 p.m. The alterations in Mg2+-ATPase activity in their magnitude and circadian rhythm coincided completely with the daily variations in content of radiophosphorus. Activities of Na+, K+- and HCO(3-)-ATPases exhibited maximal values at 15 p.m. and, especially between 3 and 6 a.m., i.e. these alterations were of two-peak shape without the peak at 21 p.m.

[Specific resistance and electrophoretic mobility of regenerating liver cells. Effect of ribonuclease and neuraminidase]. / Udel'noe soprotivlenie i élektroforeticheskaia podvizhnost' kletok regeneriruiushchei pecheni. Vliianie ribonukleazy i neiraminidazy

Changes of specific resistance and electrophoretic mobility of the cells from regenerative liver of rats are investigated. It is shown that specific resistance decreases and electrophoretic mobility increases during 30 h after hepathectomy. Exogenous ribonuclease decreases electrophoretic mobility by 10% and does not reduce significantly specific resistance. Neuraminidase treatment caused a marked increase (approximately 40%) of specific resistance without reduction in the mobility of cells from both intact and regenerative liver. It is concluded that there is no difference in the sensitivity of the cell surface of normal and regenerative liver to ribonuclease and neuraminidase.