VOL. 12 (1953) ASCITIC TUMORS AND THEIR HOST'S BLOOD PLASMAS 169 



The difference in response to anaerobic incubation of the EhrHch ascites carcinoma 

 and of the dba ascites thymoma might be ascribed in part to the differences in cell 

 volume per ml of the cell suspensions of the two tumors. The cell volume of the Ehrlich 

 tumor cell suspension generally comprised 35 to 25% of the total while that of the dba 

 tumor cell suspension varied from 30 to 15% of the combined cell and ascitic fluid 

 volume. The higher percentages were associated with the younger tumors (5- to 6-day 

 old). However, when we brought the cell volume of a lo-day old thymoma cell suspension 

 up to that of a lo-day old Ehrlich tumor suspension (295 mm^ cells/ml suspension) 

 and incubated both suspensions anaerobically for one and one-half hours, we observed 

 only an 18% increase in aldolase activity of the thymoma ascitic fluid compared to a 

 327% increase in that of the Ehrlich carcinoma. The corresponding values for the a- 

 glycerophosphate dehydrogenase were 40% and 265% increase in activity of the treated 

 samples over that of the freshly drawn ascitic fluids. It is of interest to note that the 

 per cent increases of both enzyme concentrations following anaerobic incubation of the 

 Ehrlich ascites carcinoma were unusually high. Our evidence suggests that this fact 

 is due to the preliminary centrifugation of the cell suspensions (500 g) carried out with 

 both tumors followed by resuspension in their respective ascitic fluids to increase the 

 thymoma cell concentration to its proper value and to have a fitting control in the Ehr- 

 lich carcinoma. Worthy of further note is the fact that the percentage rise in enzyme 

 concentration in the incubated ascitic fluid of the Ehrlich tumor was disproportionately 

 dependent upon the per cent cell volume. For example, in the experiment just cited, when 

 we reduced the Ehrlich tumor cell volume from 295 to 148 mm^ per ml of cell suspension, 

 the percentage increase in aldolase activity of the incubated ascitic fluid over that of the 

 fresh fluid was only 67% rather than the 327% increase of the 2 fold more concentrated 

 cell suspension in the same ascitic fluid. The percentage increase values of the a- 

 glycero phosphate dehydrogenase concentrations were likewise disproportionately 

 lower, namely, 56%, in comparison with the 265% of the 2 times concentrated cell 

 suspension. 



In an attempt to determine the relative concentrations of aldolase and of a-glycero- 

 phosphate dehydrogenase in the cells of both the Ehrlich carcinoma and the dba thymoma 

 with respect to their ascitic fluids, we prepared homogenates of cells of both tumors 

 before and after incubation in nitrogen. For this purpose glass homogenizers, cooled in 

 an ice bath, were used and the cells were extracted by two (for Ehrlich carcinoma) and 

 four ("for dba thymoma) repeated homogenizations with physiological saline. The results 

 showed that, volume for volume, the cells of both tumors contained essentially equivalent 

 concentrations of the two enzymes. In the case of the Ehrlich ascites carcinoma, the 

 concentration of aldolase in one ml of packed fresh cells was approximately 116 times the 

 concentration found in one ml of ascitic fluid while one ml of packed fresh thymoma cells 

 contained roughly 25 times the concentration of aldolase found in one ml of the fluid. 

 The corresponding values for a-glycerophosphate dehydrogenase concentrations were 

 45 for the Ehrlich tumor cells and 18 for the thymoma tumor cells. In the course of 

 extraction of the nitrogen incubated cells it was noted that with respect to both enzymes 

 of the dba thymoma, 85 to 90% of the total in the cells was extracted into the saline 

 solution after two homogenizations, the first accounting for 60% of the total, while four 

 treatments were required of the fresh cells to give comparable (85-90%) yields, the first 

 homogenization of the four yielding only 25 to 30% of the total. With the nitrogen 

 incubated Ehrlich tumor cells, almost all of the aldolase and a-glycerophosphate dehydro- 

 References p. iji. 

 II 



