FREE AMINO ACIDS IN ANIMAL TISSUE Sus 
differs from the former by a single histocompatability gene and in which the tumor 
grows initially and then regresses”®. The amino acid patterns of the solid form of 
the tumor were virtually identical in both sublines for the first 8 days after trans- 
plantation. Subsequently the patterns diverged. The tumors in the resistant strain 
showed appearance of free glutamine while this amino acid was not detected at any 
time on the chromatograms of extracts from tumors grown in the susceptible subline. 
Also, there were relative increases in the content of free glutamic acid in the tumor 
in the resistant subline (Figs. 121-132). Similar observations were made with an 
ascites form of tumor C1498 grown in the above two sublines of mice. The results 
showed that glutamine eventually appeared in the cells and ascitic fluid in the 
resistant strain but was not detectable in either the cells or the fluid of the susceptible 
mice at any time (Figs. 133-140). 
A detailed study was then made of the cytological characteristics of the Yoshida 
ascites tumor cells and of the content of the ninhydrin-reactive constituents detected 
on two-dimensional paper chromatograms from extracts of cells and ascitic fluid at 
various times after transplantation into susceptible rats (J strain) (Figs. 141-148), 
in which the tumor grows progressively and kills the animal in approx. 14 days, 
and into a resistant rat strain (Wistar) (Figs. 149-156) in which the tumor grows 
initially but regresses completely within 8 days**. At all times after transplantation 
the content of the free or easily extractable glutamine was higher in the cells grown 
in the resistant rats. The chemical findings, generally, were similar to those observed 
in the experiments with the mice bearing the C1498 leukemia. 
Free amino acids of tumors after treatment with cytotoxic agents 
A detailed analysis was made of the sequential changes in the amino acid patterns 
of the extracts of the cells and fluid of the Yoshida sarcoma in rats after the adminis- 
tration of sarkomycin, nitromin, or crude podophyllin, and of the Ehrlich ascites 
tumor in mice after the injection of maleuric acid, sarkomycin and E-39 (2,5-di-n- 
propoxy-3,6-bis-ethyleniminobenzoquinone)**. These agents alone and in com- 
bination produced different types of cytological damage and an attempt was made 
to correlate the type and extent of histologically observable abnormality produced 
with the chromatographic patterns found. 
Sarkomycin (active material, 2-methylene-3-oxocyclopentanecarboxylic acid) is a 
weak antibiotic which produces both nuclear and cytoplasmic damage in ascites 
tumor cells. The effects upon the Yoshida tumor grown in a Wistar rat are shown in 
Figs. 157-168. After removal of the control sample (Figs. 157-159), 1 ml of physio- 
logical saline containing 50 mg of sarkomycin was injected intraperitoneally into 
a rat on the 5th day after intraperitoneal inoculation of the Yoshida tumor. Samples 
of tumor were removed at intervals up to 300 min, at which time the intraperitoneal 
cellular reaction became marked, and no further cytological or chemical studies 
were made. The control sample showed a high mitotic index (Fig. 157) and the 
chromatograms of the cells (Fig. 158) and fluid (Fig. 159) showed typical patterns 
of free amino acids for this tumor grown in Wistar rats, small amounts of glutamine 
being noted in the cells but not in the fluid. 30 min after the injection, most of the 
tumor cells showed cytoplasmic blebbing and chromosomal abnormalities (Fig. 160) 
while the cells showed a greatly elevated level of free glutamine (Fig. 161), a small 
References p. 348/349 
