EFFECTS OF PH ON CYTOTOXICITY OF CARBOQUONE TANIGUCHI, Shun'ichiro; KIMURA, Noritaka T.; BABA, Tsuneo
Japanese journal of pharmacology,
1981, 1981-00-00, Letnik:
31, Številka:
2
Journal Article
Odprti dostop
To assess the effects of pH on the cytotoxicity of carboquone (CQ), use was made of the mouse tail skin and HeLa cells in culture. CQ had the most potent cytotoxic effect at pH 6 rather than at pH 7 ...or 8. Regarding the interaction between 14C-CQ and HeLa cells, both the intracellular accumulation of free 14C-CQ and the ratio of bound 14C-CQ to total 14C-CQ uptake were enhanced at pH 6. Among the fractionated biomolecules of DNA, RNA and protein, DNA was the most active in binding CQ, under the same conditions of pH. The 14C-CQ binding to nucleic acids at pH 6 was more apparent than was the binding to protein. Thus, the enhancement of CQ cytotoxicity at low pHs is probably due to an increase in the intracellular accumulation of free CQ as well as to an enhanced reactivity of CQ with DNA, within the ranges of a lower pH.
Neoplastic changes (multiple benign adenomatous nodules) were induced in the liver of all the female rats which had ingested over 1, 200mg of polychlorinated biphenyls (PCB) during over 400 days. In ...contrast, no such neoplastic changes were observed in the comparable male rat group.
Although the Richardson method is known as an accurate method for determining the glass transition temperature of a polymer from its thermogram obtained by differential scanning calorimetry (DSC), ...the application of this method is limited in the literature. It was shown that the analysis by this method may be carried out on a personal computer with a commercially available software: it is no longer necessary to write, for this purpose, a program compatible to a particular DSC apparatus.
Cellulose/poly (N-vinylpyrrolidone) (CELL/PVP) composites were synthesized via photo-initiated polymerization in a gel state of cellulose swollen in N-vinylpyrrolidone (VP) monomer containing a small ...amount of cross-linking agent, ethylene glycol dimethacrylate. The cellulose gels were formed from solutions in dimethylacetamide-lithium chloride by coagulation with ethanol, followed by exchange of the coagulant into VP monomer as reactive impregnant. The thermal transition behavior and phase consiruction of the CELL/PVP composites obtained over a wide composition range were characterized mainly through DSC and dynamic mechanical analysis. For compositions rich in PVP (CELL<15wt%), it was resonably assumed from swellig and viscoelastic data that an original structure of cellulose gels was successfully fixed into the polymerized bulks, resulting in the formation of an interpenetrating network (IPN) type organization. However, these PVP-rich samples gave a Tg value lower than that of PVP alone. Some potential effects due to a specific interaction between cellulose hydroxyls and VP carbonyls in the process of photopolymerization are discussed.
A series of in vitro experiments have been carried out with the commercially available anticancer drugs in order to find which drug, when used in the acidic condition induced by tumor cell ...glycolysis, displays the strongest tumoricidal activity not to be expected from the conventional mode of administration. For this purpose, Ehrlich ascites tumor cells were incubated, without shaking, together with the test drug dissolved in various vehicles such as 5% aqueous glucose solution, 5% glucose in phosphate buffer, and phosphate-buffered saline. The cytocidal effect of these drugs on the tumor cells was assayed by transplanting the treated cells intraperitoneally in mice. Among the drugs tested, Carbazilquinone revealed the strongest cytocidal effect, especially when dissolved in aqueous glucose solution but not in other vehicles. This result shows that Carbazilquinone has responded to our anticipation as being cytocidally the most effective when employed in combination with cancer cell glycolysis, probably because of its chemical composition of containing aziridine groups.
Pigeon-egg sized V2 carcinoma and its lymph node metastasis of the rabbit legs were completely regressed by the present perfusion-circulation stop chemotherapy using Carbazilquinone glucose solution. ...Normal surrounding tissues of the legs were fairly intact.
Anticancer effect of carboquone was notably potentiated in tumor-bearing mice when they were pretreated with 5% glucose solution in the system of blood flow-interrupting hyperthermic chemotherapy. It ...was further found by quantitative analysis that the potentiation was much greater than increase in the general toxicity of the drug by administration of glucose. Mitomycin-C, on the other hand, revealed no such marked effect though it is considerably similar to carboquone in chemical structure.
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