Accumulation of amethopterin by L1210 and Ehrlich ascites cells in miro was mediated by a slow, temperature-sensitive, and partly saturable process. The structural specificity of the proc ess could be measured by competition studies; differences were found between the two cell lines. At physiologic drug levels, i.e., those found in vivo during drug therapy, concentrativi uptake of amethopterin ...

Purified diphtheria toxin is shown to inhibit protein synthesis in Ehrlich-Lettré ascites carcinoma cells in vitro. Protein synthesis in Ehrlich-Lettré cells is at least 10,000 times more sensitive to toxin than protein synthesis in normal mouse spleen or thymus cells. This sensitivity correlates with the observation that Ehrlich-Lettré tumors regress in mice injected with diphtheria toxin but ...

Treatment of mice bearing an Ehrlich ascites tumor with nitrogen mustard (HN2) results in an increase in the level of activity of the enzyme nicotinamide adenine dinucleotide glycohydrolase (EC 3.2.2.5) (1, 2). Comparison of some properties of this enzyme in homogenates of Ehrlich ascites cells from nitrogen mustard-treated and from untreated mice failed to reveal marked differences between the...

The rapid rate of growth and multiplication of the Ehrlich mouse ascites carcinoma cells (6) indi cates the need for large amounts of nutrients for the production of protoplasm and the acquiring of energy for those synthetic processes. Recently, Christensen and Riggs (2) and Christensen, Riggs, Fischer, and Palatine (3) have reported the strik ing ability of this tumor cell to concentrate amino...

The IHD-T strain of vaccinia virus exhibited an oncolytic effect upon Ehrlich ascites tumor cells proliferating in the peritoneal cavity of the mouse. Either premature death or a prolonged survival time of tumor-bearing mice might result depending on whether the virus was inoculated into an established tumor (5 days) or whether it was inoculated simultaneously with, or 2 days after, the tumor c...