Detail of "63-89-8"

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Modulation of the cellular toxicity of nitrogen mustard in murine cells

Modulation of the cellular toxicity of nitrogen mustard in murine cells. Ritter, Carl; Rutman, Robert J.; Goldstein, Norma O. (Sch. Vet. Med., Univ. Pennsylvania, Philadelphia, PA 19104, USA). Cancer Res., 47(2), 472-6 (English) 1987. CODEN: CNREA8. ISSN: 0008-5472. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) Section cross-reference(s): 1 A linear increase in cell uptake of nitrogen mustard (HN2) [55-86-7], between 1 and 5 min, was obsd. after in vitro incubation of Ehrlich ascites tumor cells at 37° in phosphate-buffered saline contg. HN2 followed by washing in 0° phosphate-buffered saline. After a 2nd incubation in 37° phosphate-buffered saline without HN2, the cells lost ~0.5 of the drug which had been taken up, that which had not been covalently bound to macromols. The basal cytotoxic effect of HN2 on the cells was detd. using a std. in vivo test for cell viability. Host survival was measured after 105 HN2-treated cells were injected i.p. into recipient mice, compared with the injection of 105 untreated cells into paired control mice. Five-min incubation of cells in vitro with multilamellar liposome vesicles (MLV) composed of L(a)dipalmitoylphosphatidylcholine [63-89-8] in the presence of HN2 significantly increased tumor cell kill and mouse survival over HN2 alone. In contrast, added Ca2+ plus HN2 decreased cytotoxicity and survival. Significant increases in host survival following MLV treatment occurred without significant increase in total HN2 uptake and could be highly correlated with increased amts. of HN2 bound to DNA. The addn. of vincristine [57-22-7] (an inhibitor of microtubule polymn.) in the presence of HN2 also decreased the cytotoxic effect of HN2 uptake, whether L(a)dipalmitoylphosphatidylcholine MLV were present or not. Evidently, Ca2+ and MLV act at membrane sites so as to alter the subcellular distribution and localization of HN2 and its accessibility to crit. targets.Except for chemicals metioned above, 57-22-7 and 7440-70-2 are also used. This has been confirmed for MLV by demonstrating increased alkylation of DNA. .

The role of lipid fluidity in the interaction of DDT and some analogs with synthetic membranes

The role of lipid fluidity in the interaction of DDT and some analogs with synthetic membranes. Chefurka, W.; McLeod, H. L.; Steele, J. E. 72-55-9 and 4235-95-4 are also occured in this study. (Res. Cent., Agric. Canada, London, ON N6A 5B7, Can.). Pestic. Biochem. Physiol., 28(1), 93-102 (English) 1987. CODEN: PCBPBS. ISSN: 0048-3575. DOCUMENT TYPE: Journal CA Section: 5 (Agrochemical Bioregulators) The incorporation of 2 active chlorinated hydrocarbon insecticides (DDT [50-29-3] and 1,1,1-trichloro-2,2-bis(p-methoxyphenyl)ethane [72-43-5] and inactive DDE [72-55-9] into vesicles of dipalmitoyl-L-a-phosphatidylcholine [63-89-8], dimyristoyl-L-a-phosphatidylcholine [18194-24-6], dioleoyl-L-a-phosphatidylcholine [4235-95-4], and egg phosphatidylcholine was studied by discontinuous sucrose gradient centrifugation. The extent of incorporation was used in the calcn. of their partition coeffs. and soly. in phospholipids. A fluid bilayer was essential for high incorporation. The partition coeffs. and membrane satn. capacities were higher in fluid than in rigid membranes. Depending on the chem., the lipid/aq. partition coeffs. were 1-3-fold lower than the octanol/water partition coeff. No significant difference was noted in these parameters for the 3 chem. even though their hydrophobicities, as judged by their water solubilities, differed by about 2-fold, suggesting that hydrophobicity does not ensure high lipophilicity. Furthermore, the lack of correlation between these parameters and insecticidal activity indicates that the biol. activities of these insecticides is not the result of specific interactions with the membrane lipids per se. A comparison of literature data with respect to the relative fluidity of various insect and mammalian membranes shows that insect membranes are strikingly more fluid. This would favor greater accumulation of chlorinated hydrocarbons into the unsatd. membranes as the first step in their action on a membrane-assocd. target site(s), and perhaps would partially explain their generally higher toxicity to insects. .